An encryption algorithm which utilizes the DES algorithm three times in succession.
See Asynchronous Control Character Mask.Related terms: asynchronous control character mask
An acknowledge signal or message. For IP session establishment, an ACK message is sent in response to a SYN message.Related terms: SYN
acknowledge signal (ACK)
An acknowledge signal or message. For IP session establishment, an ACK message is sent in response to a SYN message.
address resolution protocol (ARP)
The Internet protocol used to map an IP address to a MAC address. Defined in RFC 826.
Advanced Encryption Standard (AES)
A new encryption algorithm which may be used in any bit length. Popular bit lengths are 128 and 256 bits.
advanced stream scheduler
An Ixia hardware capability for some POS cards that allows an interleaved set of streams to be sent to the DUT.
The router process in which routing or service updates are sent at specified intervals so that other routers on the network can maintain lists of usable routes.
See Advanced Encryption Standard.
An IKE Phase 1 mode in which only three message are exchanged. Identities transmitted during this type of negotiation are sent in the clear and not protected.Related terms: Phase 1
Alarm Indication Signal used in POS transmissions. Included as a setting in the K2 byte.
See Application Programming Interface.
application programming interface (API)
A set of supplied program modules and environment used to provide support in building a software application.
See Automatic Protection Switching.
are you there (AYT)
Any packet (for example, an ARP Request) that produces a response, sent to determine whether the DUT is able to respond.
area border router (ABR)
Router located on the border of one or more OSPF areas that connects those areas to the backbone network. ABRs are considered members of both the OSPF backbone and the attached areas. They therefore maintain routing tables describing both the backbone topology and the topology of the other areas.
See Address Resolution Protocol.
See Autonomous System and Available Seconds.
asynchronous control character mask (ACCM)
A 32-bit mask that represents control characters with ASCII values 0 through 31. If a bit is set to 1, PPP encodes the corresponding control character before sending it over the link.
An event that can happen at any time. In the Ixia system, an asynchronous interrupt can trigger the transmission of an asynchronous region.
A set of streams that can be triggered and transmitted at any time.
The particular algorithm used in calculating an authentication header. For example, the algorithms supported by IxVPN are MD5 and SHA-1.Related terms: SHA-1
authentication header (AH)
A security protocol that provides data authentication and optional anti-replay services. AH is embedded in the data to be protected (a full IP datagram).
The algorithm that allows two devices at either end of a link segment to negotiate common data service functions.
automatic protection switching
A technique used in Packet over SONET networks to switch working channels to backup protection channels.
autonomous system (AS)
A collection of routers that implement the same routing policy and are typically administered by a single group of administrators. ASs connected to the Internet are assigned numbers called ASNs (autonomous system numbers) which are key to inter-domain routing
autonomous system boundary router (ASBR)
ABR located between an OSPF autonomous system and a non-OSPF network. ASBRs run both OSPF and another routing protocol, such as RIP. ASBRs must reside in a nonstub OSPF area.
During PoS data reception, the seconds during which the block state was in an available condition; generally error free for 10 seconds or more.
Part of a network that acts as the primary path for traffic that is most often sourced from, and destined for, other networks.
base station (BS)
In wireless networks, the non-mobile part of the connection. The base station is responsible for sending and receiving data to Mobile Stations and wide-area networks.
See Bit Error Rate Testing.
See Border Gateway Protocol.
Bit Interleaved Parity errors found in POS circuits. BIP errors can occur as Section, Line, or Parity errors.
bit error rate testing (BERT)
An OSI Layer 1 test in which low level data integrity is tested.
bit interleaved parity errors (BIP errors)
Bit Interleaved Parity errors found in POS circuits. BIP errors can occur as Section, Line or Parity Errors.
Bootstrap Protocol. Protocol used by a network node to determine the IP address of its Ethernet interfaces, in order to affect network booting.
bootstrap protocol (BOOTP)
Bootstrap Protocol. Protocol used by a network node to determine the IP address of its Ethernet interfaces, in order to affect network booting.
border gateway protocol (BGP)
The principal protocol used along the Internet backbone and within larger organizations.
border gateway protocol version 4 (BGP4)
Interdomain routing protocol that exchanges reachability information with other BGP systems. It is defined by RFC 1163. BGP4 supports CIDR and uses route aggregation mechanisms to reduce the size of routing tables.
Bridge Protocol Data Unit. A Spanning-Tree Protocol Hello packet that is sent out at configurable intervals to exchange information among bridges in the network.
bridge protocol data unit (BPDU)
A spanning-tree protocol hello packet that is sent out at configurable intervals to exchange information among bridges in the network.
See Base Station.
A counted number of data packets, each separated by an Inter-Packet Gap (IPG).
A pair of related computer programming languages. Ixia supplies an API for the use of C++ in test development.
The CPE in a cable data system. The cable modem handles RF signals from the cable network and ethernet/USB signals on the local network.
cable modem termination system
The central office equipment in a cable data network. The CMTS handles RF signals form the cable network and ethernet signals to the wide-area network.
A basic receive mode – as opposed to packet group mode.
A memory area associated with each port. Data is captured after the Capture Trigger is satisfied and the Capture Filter allows data to be recorded.
A set of conditions that determine which data is recorded in a port’s capture buffer.
A set of conditions that determine which when data is starts to record in a port’s capture buffer.
card module (CM)
A plug-in card that fits within an Ixia chassis and contains one or more ports.
A feature of the Ixia User Defined Fields that allows counting to continue from previous streams.
See Converged Data Link.
Code-Division Multiple Access. A technique used in cellular phone/data systems to allow multiple coded transmissions on the same frequency range.
challenge handshake authentication protocol (CHAP)
A protocol that runs over LCP and is used to authenticate connections over a PPP connection.
A transmission option for subscribers of symmetrical services. Channelized service allows a subscriber to assign one device (such as a PC) to a DS0 channel, resulting in many devices being able to transmit and receive simultaneously at 64 kbps.
An Ixia component that holds 1-16 load modules, Central Processing Unit, and disk.
Two or more Ixia chassis connected together through special sync-in/sync-out cables. Load modules in a chassis chain are synchronized to within 10 ns.
A value calculated from packet data which, when included with the packet, may be used to guarantee the validity of received data.
Cisco Frame Relay
A Cisco proprietary version of Frame Relay.
In C++ programming, the definition of a set of related data members and subroutine methods used to implement operations of a particular type or on a particular set of data.
classless interdomain routing (CIDR)
Technique supported by BGP4 and based on route aggregation. CIDR allows routers to group routes together to reduce the quantity of routing information carried by the core routers. With CIDR, several IP networks appear to networks outside the group as a single, larger entity. With CIDR, IP addresses and their subnet masks are written as four octets, separated by periods, followed by a forward slash and a two-digit number that represents the subnet mask.
As an IxLoad component, a simulation of a user operating a Web browser. Clients are simulated by software on CPUs associated with ports on specialized load modules.
Client to LAN
A type of IPSec network connection in which a client computer serves as its own security gateway.
See Cable Modem.
See Cable Modem Termination System.
A condition that results from concurrent transmissions from multiple sources.
An algorithm which each transmitting party uses to determine when to attempt a retransmit in the event of a collision.
C functions that are used by multiple IxANVL tests and which are stored in the ANVLUtil directory in an IxANVL distribution.
A transmission option for subscribers of symmetrical services. Concatenated service applies all of the bandwidth to a single stream.
The number of simulated clients operating at the same moment.
The number of simulated users operating at the same moment.
An argument that is passed in to *TestsRun() and which points to an C structure containing the parsed information of the configuration file and command-line options. The config variable is visible to all tests in a test suite.
One of the two auxiliary files used by applications such as IxANVL when it is executed at the command line. This file describes the configuration of the DUT on the test network, including information such as host name and addresses available to IxANVL for use during testing. In the IxANVL GUI, the Configuration page prompts for values that correspond to each entry in the configuration file. See also parameter file.
A network level, end-to-end connection between a client and a server.
The rate at which new connections are made.
A memory block that is used to pass information between two separate functions that do not call each other directly. In IxANVL it is used for handlers and timed event functions.
A control connection operates in-band over a tunnel to control the establishment, release, and maintenance of sessions and of the tunnel itself.
converged data link (CDL)
The converged data link (CDL) is a CISCO developed technology that provides a standard method of implementing operation, administration, maintenance, and provisioning (OAM&P) in Ethernet packet-based optical networks without using a SONET/SDH layer.
A memory element used by Web browsers and servers. Data is transmitted by a server back to a client, which holds that information and resubmits it as part of subsequent requests to the same server.
See Cyclic Redundancy Check.
customer edge (CE)
Network equipment on the subscriber side of a user network interface (UNI).
cyclic redundancy check
An error-checking technique in which the frame recipient calculates a remainder by dividing the frame contents by a prime binary divisor and compares the calculated remainder to a value stored in the frame by the sending node.
See Destination Address.
data communication channel (DCC)
The SONET Data Communication Channel (DCC) based on Bellcore (now Telcordia) GRE-253-CORE guidelines. Section DCC (SDCC) uses the D1 through D3 bytes of the Section Overhead with the SONET frame for communication with network equipment. Line DCC (LDCC) uses the D4 through D12 bytes of the Line Overhead.
data link layer
Layer 2 of the OSI reference model. Provides reliable transit of data across a physical link. The data-link layer is concerned with physical addressing, network topology, line discipline, error notification, ordered delivery of frames, and flow control. The IEEE divided this layer into two sublayers: the MAC sublayer and the LLC sublayer. Sometimes simply called link layer.
Fundamental unit of information passed across the Internet. Contains source and destination addresses along with data and a number of fields that define such things as the length of the datagram, the header checksum, and flags to indicate whether the datagram can be (or was) fragmented.
See Data Communications Channel.
In IP routing procedures, the IP address of a routing device to send all packets that are not otherwise directed by a routing protocol. In Ixia testing, the DUT is often the Default Gateway.
A handler that is installed during IxANVL initialization on a node in the handler tree. Its function is to decode incoming packets and dispatch them to other handlers in the tree.
In the context of the IP protocol family, each router maintains one address which is used as the default routing address for all packets whose destination addresses do not appear in the routing table.
An IP header bit that indicates that the sender is interested in minimizing packet delay.
The process of removing a license from a particular chassis or workstation. Once a license has been deregistered, the products or services associated with the license cannot be used until a new license is acquired. Deregistration is done using the Ixia Registration Utility (IRU). Deregistrations can occur online or offline.
destination address (DA)
A Data Link Layer field that indicates the MAC level destination of the packet.
In this document, it refers to capability of IxANVL to appear as (to emulate) more than one node on the test network.
device under test (DUT)
The device that is the subject of the test. For example, a networking device that is being tested through a combination of input data and sensed output data. Or, for IxVPN, it is an IPSec security gateway.
The particular type of public-private key cryptography used to form the shared secret used to encrypt IKE message exchanges.Related terms: public-private key cryptography, shared secret
Dynamic Host Configuration Protocol. DHCP provides a mechanism for allocating IP addresses dynamically so that addresses can be reused when hosts no longer need them.
A class of algorithms developed by two mathematicians (Diffie and Hellman) which implements public-private key cryptography.Related terms: public-private key cryptography
Digital Encryption Standard (DES)
A U.S. DoD standard algorithm for data encryption. The base DES algorithm uses keys which are 56 bits long.Related terms: 3DES
distance vector multicast routing protocol (DVMRP)
Internetwork gateway protocol, largely based on RIP, that implements a typical dense mode IP multicast scheme. DVMRP uses IGMP to exchange routing datagrams with its neighbors.
distributed denial of service attack (DDoS)
An attack characterized by an explicit attempt by attackers to prevent legitimate users of a service from using that service. Examples include attempts to flood a network, to disrupt connections between two machines, to prevent a particular individual from accessing a service, and to disrupt service to a specific system or person.
A bit-oriented Ethernet header which uses bit stuffing.
See Domain Name System.
domain name system (DNS)
The system used in the Internet for translating names of network nodes into addresses.
dribble bit error
An error condition that occurs when additional data follows the FCS at the end of a packet.
The mode of an Ethernet port - either half-duplex or full-duplex.
See Device Under Test.
dynamic host configuration protocol (DHCP)
A TCP/IP protocol that allows a DHCP server to provide configuration parameters—including the allocation of IP addresses— to DHCP client hosts. RFC 2131 provides the latest DHCP definition (March 1997).
Dynamic Host Control Protocol (DHCP)
DHCP provides a mechanism for allocating IP addresses dynamically so that addresses can be reused when hosts no longer need them.
See Error Free Seconds.
In MPLS routing networks, the router by which the network was exited.
encapsulating security payload (ESP)
Security protocol that provides data privacy services, optional data authentication, and anti-replay services. ESP encapsulates the data to be protected.
One of a set of algorithms used to encrypt the encapsulating security payload. For example, the algorithms implemented by IxVPN are 3DES and AES.Related terms: 3DES, AES, encapsulating security payload
error free seconds
For PoS received data, the number of one-second periods for which no bit error or defect was detected.
In POS, the number of blocks in which one or more bits are in error.
errored seconds (ES)
For PoS received data, the number of one-second periods with one or more errored blocks or at least on defect.
See Errored Seconds.
A baseband LAN specification invented by Xerox Corporation and developed jointly by Xerox, Intel, and Digital Equipment Corporation. Ethernet networks use run over a variety of cable types at 10/100/1000 Mbps. Ethernet is similar to the IEEE 802.3 series of standards.
Ethernet virtual connection (EVC)
A type of connection used in Metro Ethernet Networks in which an association is formed between two or more UNIs. The exchange of service frames is limited to the UNIs that comprise the EVC.
Two or more Web servers which co-operate in the fulfillment of a Web site.
See Frame Check Sequence.
See Forward Error Checking.
field programmable gate arrays (FPGA)
These are programmable elements of the Ixia chassis and cards, downloaded by IxServer as needed.
(First-In, First-Out) A programming rule according to which requests from queues or stacks are handled such that the oldest request is handled next.Related terms: LIFO
See Capture Filter.
A TCP packet with the FIN bit set. This is used by one party in a connection to end a TCP connection.
A TCP packet with the FIN and ACK bits set. This is used by a party in a connection to acknowledge the conclusion of a connection.
See Frame Identity Record.
A 3-bit flag of the IP header that deals with IP fragments.
Routing problem where an advertised route between two nodes alternates (flaps) back and forth between two paths due to a network problem that causes intermittent interface failures.
A type of license that resides on a License Server and allows multiple workstations/chassis to use the product or software associated with the license. A floating license is node-locked to the License Server.
Traffic passing technique used by switches and bridges in which traffic received on an interface is sent out all the interfaces of that device except the interface on which the information was received originally.
A means of programming the Ixia transmit hardware so as to allow thousands of unique packets. These packets are pre-generated in software.
A C structure in IxANVL that contains a representation of a packet. There is one such form for each type of packet.
forward error checking (FEC)
Forward error correction is a method of communicating data that corrects errors in transmission on the receiving end. Prior to transmission, data is put through a predetermined algorithm that adds extra bits specifically for error correction to any character or code block. If the transmission is received in error, the correction bits are used to check and repair the data.
forwarding equivalence class (FEC)
A set of packets that can be bound to the same MPLS label.
Field Programmable Gate Arrays. These are programmable elements of the Ixia chassis and cards, downloaded by IxServer as needed.
A set of data formatted according to a data link standard, such as Ethernet or 802.3. Also referred to as a packet.
frame check sequence
Extra characters added to a frame for error control purposes.
frame identity record
An Ixia port capability that allows additional data to inserted at the end of the data part of a packet. This data can be used to locate the source of the frame when the frame is received in a capture buffer
A high-speed, packet-mode data communications protocol based on ITU-T recommendation I.122 and the link access procedure on the D channel (LAPD) specification. It is specifically designed for transport over today\'s reliable high-speed digital facilities.
The overall size of the frame, including the FCS.
The part of the link layer (Layer 2) that supports different media types.
The ability of a communications device to both transmit and receive at the same time.
An input/output device that plugs into a Gigabit ethernet port, linking the module port with the fiber-optic network.
generic framing procedure (GFP)
Generic framing procedure (GFP) provides a generic mechanism to adapt traffic from higher-layer client signals over a transport network. Client signals may be PDU-oriented (such as IP/PPP or Ethernet MAC), or block-code oriented constant bit rate stream (such as Fibre Channel or ESCON/SBCON).
The rate at which GET requests are made.
A statement in the HTTP protocol sent from a client to a server, requesting that the server supply a Web page identified by a URL.
See Generic Framing Procedure.
A network operating at 1000 Mbps.
Global Positioning System (GPS)
The Global Positioning System is a “constellation” of 24 well-spaced satellites that orbit the Earth and make it possible for people with ground receivers to pinpoint their geographic location. An additional benefit of GPS is the ability to derive a very accurate time-of-day.
The part of the configuration file which contains the DUT name entry as well as other protocol-specific entries that apply to all interfaces.
See Global Positioning System.
Hardware Abstraction Layer. A layer of software used to isolate the user input software from the actual hardware control.
The characteristic of a communications device that it can only transmit or receive data.
A C function that processes incoming packets. Also called handler function.
A software abstraction within IxANVL that organizes all the handlers of a particular netconn object and the protocol nodes on which they are installed.
hardware abstraction layer (HAL)
A layer of software used to isolate the user input software from the actual hardware control.
high bits of source address (HSA)
The high order 24 bits of an ISL packet’s source address.
host byte order
The ordering of bytes used by the host.
Removing and reinstalling a load module without requiring the removal of power from the rest of the chassis.
High bits of Source Address. The high order 24 bits of an ISL packet\'s source address.
hypertext markup language (HTML)
The language used to compose Web pages.
hypertext transport protocol (HTTP)
Hyper-Text Transport Protocol. The protocol used between Web clients and servers.
See Inter-Burst Gap.
Internet Control Message Protocol. A network layer Internet protocol that reports errors and provides other information relevant to IP packet processing. Documented in RFC 792.
An element of the IP header which identifies the datagram that the fragment belongs to.
IEEE LAN protocol that specifies an implementation of the physical layer and the MAC sublayer of the data link layer.
Internet Group Management Protocol. Used by IP hosts to report their multicast group memberships to an adjacent multicast router.
See Internet Key Exchange.Related terms: Internet Key Exchange
A bidirectional IDE Phase 1 SA, which is also referred to as an ISAKMP SA. It sets up a secure authenticated "control channel" for further IKE communications.Related terms: Internet Key Exchange
See Internet Mix.Related terms: Internet MIX
In MPLS routing networks, the router by which the network was entered.
The party in an IKE negotiation that starts a Phase 1 or Phase 2 negotiation. As opposed to a responder.Related terms: Phase 1, Phase 2, responder
The workstation or chassis used to register, de-register, update, or move licenses. The Installation Host must be connected to the chassis or workstation that will use the licensed product or software (it can also be the same chassis or workstation that will use the licensed product of software). An Ixia Registration Utility (IRU) must be installed on this machine
inter-burst gap (IBG)
The amount of time inserted between multiple bursts in a stream.
inter-packet gap (IPG)
The amount of time inserted between consecutive packets in a burst.
The amount of time preceding each stream in a region.
Inter-switch link (ISL)
A protocol used to inter-connect two VLAN capable ethernet switches.
An entry in the interface section of the IxANVL configuration file. It provides the operating system name and the type of the connection.
A part of the IxANVL configuration file that describes a particular network connection and all the protocols that use it.
interior gateway protocol (IGP)
Internet protocol used to exchange routing information within an autonomous system. Examples of common Internet IGPs include IGRP (Interior Gateway Routing Protocol), OSPF, and RIP.
In OSI routing, including IS-IS, an intermediate system is a router or other device that forwards as opposed to generates or uses traffic.
intermediate system-to-intermediate system (IS-IS)
IS-IS is an OSI/IP router-to-router routing technique.
Internet architecture board (IAB)
Board of internetwork researchers who discuss issues pertinent to Internet architecture. Responsible for appointing a variety of Internet-related groups, such as the IANA. The IAB is appointed by the trustees of the ISOC.
Internet assigned numbers authority (IANA)
Organization operated under the auspices of the ISOC as a part of the IAB. IANA delegates authority for IP address-space allocation and domain-name assignment to the InterNIC and other organizations. IANA also maintains a database of assigned protocol identifiers used in the TCP/IP stack, including autonomous system numbers.
Internet Control Message Protocol (ICMP)
A network layer Internet protocol that reports errors and provides other information relevant to IP packet processing. Documented in RFC 792.
Internet Engineering Task Force (IETF)
Task force consisting of over 80 working groups responsible for developing Internet standards—that is, RFCs and Internet Drafts. The IETF operates under the auspices of ISOC.
Internet Group Management Protocol (IGMP)
Internet Group Management Protocol. Used by IP hosts to report their multicast group memberships to an adjacent multicast router.
Internet Key Exchange (IKE)
A hybrid protocol which implements OAKLEYand SKEME key exchanges inside the ISAKMP framework. While IKE can be used with other protocols, its initial implementation is with the IPSec protocol. IKE provides authentication of the IPSec peers, negotiates IPSec security associations, and establishes IPSec keys. Note that IKE is an optional protocol within the IPSec framework, and keys can also be manually configured.Related terms: IPSec, OAKLEY
Internet MIX (IMIX)
A mixture of frame sizes intended to mimic the various frame sizes found in Internet traffic.
Internet protocol (IP)
A Layer 3 protocol that is the basis of TCP/IP. It provides connectionless, best-effort datagram delivery. The term IP generally refers to IP version 4.
Internet Protocol version 4 (IPv4)
The network layer protocol in the TCP/IP stack offering a connection-less internetwork service. IP provides features for addressing, type-of-service specification, fragmentation and reassembly, and security. Defined in RFC 791.
Internet Protocol version 6 (IPv6)
Also known as IPNG (IP Next Generation). A number of improvements over IPv4, including the use of 128-bit IP addresses.
Internet Security Association and Key Management Protocol (ISAKMP)
Provides a framework for authentication and key exchange but does not define them. ISAKMP is designed to be key exchange dependent; that is, it is designed to support many different key exchanges.
Internet society (ISOC)
International nonprofit organization, founded in 1992, that coordinates the evolution and use of the Internet. In addition, ISOC delegates authority to other groups related to the Internet, such as the IAB. ISOC is headquartered in Reston, Virginia (United States).
internetwork packet exchange (IPX)
NetWare network layer (Layer 3) protocol used for transferring data from servers to workstations.
Internetwork protocol control protocol (IPCP)
A control protocol for running IP over a PPP connection.
Organization that serves the Internet community by supplying user assistance, documentation, training, registration service for Internet domain names, and other services. Formerly called NIC.
IP Security (IPSec)
A framework of open standards that provides data confidentiality, data integrity, and data authentication between participating peers. IPSec provides these security services at the IP layer. IPSec uses IKE to handle the negotiation of protocols and algorithms based on local policy and to generate the encryption and authentication keys to be used by IPSec. IPSec can protect one or more data flows between a pair of hosts, between a pair of security gateways, or between a security gateway and a host.
See Inter-Packet Gap.
See IP Security.Related terms: IP Security
A bidirectional IKE Phase 2 SA, which is also referred to as an IPSec SA. It creates the secure data exchange channel.Related terms: Internet Key Exchange
Internet Protocol version 4. The network layer protocol in the TCP/IP stack offering a connectionless internetwork service. IP provides features for addresssing, type-of-service specification, fragmentation and reassembly, and security. Defined in RFC 791.
Also known as IPNG (IP Next Generation). A number of improvements over IPv4, including the use of 128-bit IP addresses.
IPSec for IPv6.
Internetwork Packet Exchange. NetWare network layer (Layer 3) protocol used for transferring data from servers to workstations.
See Intermediate System.
An OSI/IP routing technique, Intermediate System to Intermediate System. I.e. router to router
See Internet Security Association and Key Management Protocol.
See Inter-Stream Gap.
Inter-Switch Link. A protocol used to inter-connect two VLAN-capable Ethernet switches.
The part of IxANVL below the protocol stack implementations that provides services for both existing and user-written tests.
The IxANVL graphical user interface that is based on the Ixia Test Manager (ITM). Its most significant feature are the tabbed-pages that guide your progress through the setup and test processes. In addition, the GUI displays the ANVL user guides (HTML format) for the test suites included in your installation.
Any of the networks, routers, or other devices IxANVL emulates during a test. IxANVL node protocol addresses are not the same as the protocol addresses of the IxANVL workstation.
The PC-compatible system running Redhat Linux on which IxANVL runs.
6000 Unique attacks
An Ixia device that features a GPS, rubidium oscillator and additional timing inputs. An IxClock is used in conjunction with another standard Ixia chassis.
Ixia Automated Network Validation Library (IxANVL)
IxANVL is a software testing tool that validates the protocol implementations and operational robustness of networking devices including Layer 3 switches, high-density RA servers, backbone routers and end nodes. The terms “IxANVL”, “Ixia ANVL”, and “ANVL” are used interchangeably.
Ixia registration utility (IRU)
An application that controls Ixia licenses. The Ixia Registration Utility (IRU) is used to register, deregister, update, and manage licenses. It is run from the installation host.
A software tool that works in co-operation with Ixia hardware to perform Web stress testing.
An aspect of the Ixia Hardware that allows handling of IP to MAC mapping, BGP, OSPF, IGMP, IS-IS, RSVP and RIP testing.
A software module that resides on an Ixia chassis and receives commands from Unix machines running IxScriptMate or TCL-based code.
Ixia Tool Command Language/ Hardware Abstraction Layer
The Ixia Tcl Command library provides full access to the Ixia hardware platform.
Configurations can be sent to the hardware and various programs can be created
and executed on the system. Tcl scripting allows automation of testing procedures
when tens to thousands of ports are involved. Ixia’s Tcl Command Library
is built using a combination of commands that are written in Tcl and commands
that are implemented in C/C++.
A combination of an IKE Tunnel and an IPSec tunnel.Related terms: IKE tunnel, IPSec tunnel
The standard deviation of latency measurements.
Two control bytes used in POS APS.
Period of time between each keepalive message sent by a network device.
Message sent by one network device to inform another network device that the virtual circuit between the two is still active.
L2TP access concentrator (LAC)
A node that acts as one side of an L2TP tunnel endpoint and is a peer to the L2TP network server (LNS). The LAC sits between an LNS and a remote system and forwards packets to and from each. Packets sent from the LAC to the LNS require tunneling with the L2TP protocol. The connection from the LAC to the remote system is either local or a PPP link.
L2TP network server (LNS)
A node that acts as one side of an L2TP tunnel endpoint and is a peer to the L2TP access concentrator (LAC). The LNS is the logical termination point of a PPP session that is being tunneled from the remote system by the LAC.
See Layer 2 Virtual Private Network.
See Layer 3 Virtual Private Network.
The person who manages the test lab. This person will most likely be the point of contact for Ixia license information, and the one who receives the e-mail from Ixia with the registration numbers and passwords for Ixia licenses.
A person who works with the equipment in the test lab. This person will most likely use the Ixia Registration Utility (IRU) to register, de-register, update, and manage licenses.Related terms: Ixia registration utility
label distribution protocol (LDP)
A set of procedures by which LSRs distribute labels to support MPLS forwarding along normally routed paths.
label switched path
In MPLS and RSVP-TE, a path through a number of routers from an ingress to an egress router that has been established through the use of labels used in Label Switching Routers.
label switching routers (LSR)
In MPLS and other label switching environments, routers that switch traffic based on labels.
LAN to LAN
A type of IPSec network configuration in which security gateway devices connect two distributed lines via a secure tunnel.Related terms: IPSec, security gateway
See Link Alarm Status Interrupt.
The order in which IxANVL invokes handlers.
The delay between the time a device receives a frame and the time that frame is forwarded out the destination port.
layer 2 forwarding protocol (L2F protocol)
Protocol that supports the creation of secure virtual private dial-up networks (VPDNs) over the Internet.
layer 2 tunnel protocol (L2TP)
An Internet Engineering Task Force (IETF) standards track protocol defined in RFC 2661 that provides tunneling of PPP. Based upon the best features of L2F and PPTP, L2TP provides an industry-wide interoperable method of implementing VPDN.
Layer 2 Virtual Private Network
An emulation of a Layer 2 switching environment, supplied by a Service Provider for its customers, via a core network that connects customer sites. Ixia’s L2VPN emulation is an add-on option for the Label Distribution Protocol (LDP) software and simulates the transport of Layer 2 frames over MPLS.
Layer 3 Virtual Private Network
An emulation of Layer 3 services/distribution of routes, supplied by a Service Provider for its customers, via a core network that connects customer sites. Ixia’s L3VPN emulation is an add-on option for the Border Gateway Protocol (BGP) software and simulates Provider-Provisioned VPN (PPVPN) functionality per IETF Draft RFC 2547bis.
See Line Control Protocol.
Official permission from Ixia to use specified products or software for a specific number of machines. A license is contained in a license file.
A file that is placed on a chassis or workstation that contains license information for products or software. A license file uses the extension .lic, and is a text file. Any changes made to a license file invalidate the license.
A workstation or chassis that distributes licenses to a group of machines. License servers can monitor node-locked or floating licenses.
(Last-In, First-Out ) A programming rule according to which the most recent request is handled next and the oldest request gets handled only when it becomes the sole remaining request in the queue (or in the stack).Related terms: FIFO
line control protocol (LCP)
A part of the PPP protocol used to control the communications line.
A particular type of BIP Errors found or inserted in POS systems.
For 10/100/1000 Mbps ports, the choice of which speed is selected.
Implementation of a POS APS for an arrangement of nodes that are configured as a string.
link aggregation control protocol (LACP)
Part of an IEEE specification (802.3ad) that allows you to bundle several physical ports together to form a single logical channel. LACP is a layer 2 protocol implementation that allows a switch to negotiate an automatic bundle by sending LACP packets to the peer. If the first link goes down, traffic will be routed through an alternate link.
link alarm status interrupt (LASI)
The link alarm status interrupt (LASI) is an active-low output from the XENPAK module that indicates a link fault condition has been asserted or has been cleared. Control registers are provided so that LASI may be programmed to assert only for specific fault conditions.
link state advertisement (LSA)
An element of an OSPF message that indicates the state of a router’s link, including additional attributes.
link-state advertisement (LSA)
Broadcast packet used by link-state protocols that contains information about neighbors and path costs. LSAs are used by the receiving routers to maintain their routing tables. Also called link-state packet.
A technique by which processing requests are shared among a number of servers, so as to even the load between servers and minimize user response time.
load balancing switch
A device that implements a load balancing algorithm.
An Ixia card component which resides in an Ixia chassis and contains one or more ports.
An IxANVL command-line option that specifies the amount of detail displayed during IxANVL execution. -l controls the general log level, while -o controls the outbound log level. The log level can be high, medium, or low.
The condition in which a port’s transmitter and receiver are connected together to test basic port operation.
See Link State Advertisement.
See Label Switched Path.
See Label Switching Routers.
A PPP negotiation feature used primarily to detect looped connections.
An IKE Phase 1 modes in which only six message are exchanged. Identities transmitted during this type of negotiation are encrypted.Related terms: Phase 1
The left part of an IxANVL test number.
A text file which contains commands and consistency rules and is used to compile and link software systems (such as IxANVL).
A component of IxLoad which operates the GUI software. The management station must be a Windows 95, 98, or 2000 machine.
A mode of running IxANVL tests. When an action needs to be performed on the DUT, IxANVL pauses and instructs the user to perform the action manually.
media access control (MAC)
The data link sublayer that is responsible for transferring data to and from the Physical Layer.
media independent interface registers (MII registers)
A set of data registers which control the operation of the PHY.
In C++ programming, a data item associated with a Class.
Application layer (Layer 7) logical grouping of information, often composed of a number of lower-layer logical groupings, such as packets. The terms datagram, frame, packet, and segment also are used to describe logical information groupings at various layers of the OSI reference model and in various technology circles.
Message Digest 5 (MD5)
A widely-used cryptographic hash function with a 128-bit hash value. As an Internet standard (RFC 1321), MD5 has been employed in a wide variety of security applications, and is also commonly used to check the integrity of files.
In C++ programming, a subroutine associated with a Class.
Media Independent Interface. A set of data registers which control the operation of the PHY.
The right part of an IxANVL test number.
mobile station (MS)
In a wireless network, the mobile component of the system. It deals with CDMA signal to ethernet signal translation.
An IPSec feature that functions like DHCP for IPSec clients. Modecfg enables a responder to send (push) addresses (such as a private IP address, a DNS server\'s IP address) to an initiator.Related terms: initiator, IPSec, responder
Multi-protocol layered switching. A protocol for controlling wide area routing.
See Mobile Station.
Multi-protocol layered switching (MPLS)
A protocol for controlling wide area routing.
Multicast is communication between a single sender and multiple receivers on a network. Multicast addresses are assigned from the 224.*.*.* range.
Router used to send IGMP query messages on their attached local networks. Host members of a multicast group respond to a query by sending IGMP reports noting the multicast groups to which they belong. The multicast router takes responsibility for forwarding multicast datagrams from one multicast group to all other networks that have members in the group.
multilink PPP (MLP)
Method of splitting, recombining, and sequencing datagrams across multiple logical data links.
multiprotocol label switching (MPLS)
Switching method that forwards IP traffic using a label. This label instructs the routers and the switches in the network where to forward the packets based on preestablished IP routing information.
See Network Control Protocol.
A type of testing in which the IxANVL sends badly formed packets to the DUT to determine how it operates in an environment containing other, less robust nodes.
A software abstraction within IxANVL of a physical point of attachment to the test network. For each interface section in the IxANVL configuration file, there is one netconn object.
Network Address Translation Traversal (NAT-T)
Described in RFC 3947 and 3928, it was developed to address the problem of using IPSec over NAT devices.
network byte order
The ordering of bytes used by the network attached to IxANVL.
Layer 3 of the OSI reference model. This layer provides connectivity and path selection between two end systems. The network layer is the layer at which routing occurs.
network layer reachability information (NLRI)
BGP sends routing update messages containing NLRI to describe a route and how to get there. In this context, an NLRI is a prefix. A BGP update message carries one or more NLRI prefixes and the attributes of a route for the NLRI prefixes; the route attributes include a BGP next hop gateway address, community values, and other information.
A set of bits that indicates that part of an IP address that corresponds to the network number. A network mask must have a contiguous set of “1” from its MSB.
An endpoint of a network connection or a junction common to two or more lines in a network. Nodes can be processors, controllers, or workstations. Node is sometimes used generically to refer to any entity that can access a network, and is frequently used interchangeably with device.
That part of an IP address that corresponds to the network being addressed. Formed by adding the Network Mask with the IP address.
Each Network Node has 64k connection endpoints called sockets that are used in IP communications.
Half of a byte; four bits.
An ID number assigned to a chassis or workstation by the Ixia Registration Utility (IRU) for identification purposes.
A license that is anchored to a specific chassis or workstation. The products or software controlled by the license can only be used on one chassis or workstation at a time.
Resource-intensive OSPF area that carries a default route, static routes, intra-area routes, interarea routes, and external routes. Nonstub areas are the only OSPF areas that can have virtual links configured across them, and are the only areas that can contain an ASBR.
NSSAs are similar to the existing OSPF stub area configuration option but have the additional capability of importing AS external routes in a limited fashion (RFC 1587).
The NULL encryption algorithm is a convenient way to represent the option of not applying encryption.Related terms: encryption algorithm
Defined in RFC 2412, it describes a series of key exchanges, called modes, and details the services provided by each (for example, Perfect Forward Secrecy for keys, identity protection, and authentication).Related terms: Perfect Forward Secrecy
If the Installation Host is not connected to the Internet (and therefore cannot reach the Ixia Registration Server) when registering, de-registering, or updating a license, the Installation Host is considered to be offline.
If the Installation Host is connected to the Internet (and can reach the Ixia Registration Server) when registering, deregistering, or updating a license, the Installation Host is considered to be online.
The chassis or workstation used to connect to the Ixia Registration Server (via the Internet) when registering, de-registering, or updating a license from an Installation Host in the offline state.
open shortest path first
A set of messaging protocols that are used by routers located within a single Autonomous System (AS).
See Open Shortest Path First.
A logical grouping of information that includes a header containing control information and user data. Packets are most often used to refer to network layer units of data. The terms datagram, frame, message, and segment are also used to describe logical information groupings at various layers of the OSI reference model.
A basic mode of Ixia ports which allows transmitted packets to be grouped by the inclusion of an ID within the packet. The Ixia receive hardware then has the ability to categorize latency for each distinct packet group.
A software abstraction that contains the entire packet as it was received from the physical link. A packet history exists only while the packet travels up the handler tree.
packet over SONET (POS)
The ability to include IP packets within SONET payloads.
A software abstraction within IxANVL for reading packets from the physical link and writing packets to it.
One of the two auxiliary files used by IxANVL. It contains information such as settings that specify capabilities (or limitations) of the specific DUT or commands that configure the DUT for certain tests. In the IxANVL GUI, the Parameters page prompts for values that correspond to each entry in the parameter file.
password authentication protocol (PAP)
An unencrypted protocol that runs over LCP and is used to authenticate user names and passwords over a PPP connection. It is simpler and less secure than CHAP.
A particular type of BIP Errors found or inserted in POS systems.
A mode of IxANVL execution (triggered by the -p command-line option) in which IxANVL pauses and prompts the user before and after each test.
See Powered Device.
See Protocol Data Unit.
Router or device that participates as an endpoint—for example, in IPSec and IKE. When used in context with L2TP, peer refers to either the LAC or LNS. When used in context with PPP, a peer is either side of the PPP connection.
Perfect Forward Secrecy (PFS)
A technique by which each IKE Phase 2 negotiation generates a new shared secret.Related terms: Phase 2, shared secret
The interval between subsequent invocations of a timed event function.
Packet Group ID. See Packet Groups.
The part of the IKE protocol that creates an SA, which is used to protect communications between security gateway devices.
The part of the IKE protocol that used the Phase 1-created SA to establish the security parameters used to authenticate and encrypt bulk network traffic using IPSec.Related terms: Phase 1
Physical Layer entity. The PHY contains the functions that transmit, receive and manage the encoded signals that are impressed on and recovered from the physical medium.
PIM--dense mode (PIM-DM)
One of the two PIM operational modes. PIM dense mode is data-driven and resembles typical multicast routing protocols. Packets are forwarded on all outgoing interfaces until pruning and truncation occurs. In dense mode, receivers are densely populated, and it is assumed that the downstream networks want to receive and will probably use the datagrams that are forwarded to them. The cost of using dense mode is its default flooding behavior.
PIM--sparse mode (PIM-SM)
One of the two PIM operational modes. PIM sparse mode tries to constrain data distribution so that a minimal number of routers in the network receive it. Packets are sent only if they are explicitly requested at the RP (rendezvous point). In sparse mode, receivers are widely distributed, and the assumption is that downstream networks will not necessarily use the datagrams that are sent to them. The cost of using sparse mode is its reliance on the periodic refreshing of explicit join messages and its need for RPs.
See Power over Ethernet.
Point to Point Protocol (PPP)
A protocol used to establish point to point connections. Most often used in dial-up connections. PPP is also used in Packet Over SONET connections and is simulated by Ixia ports.
Interface on an internetworking device (such as a router).
In IP terminology, an upper-layer process that receives information from lower layers. Ports are numbered, and each numbered port is associated with a specific process. For example, SMTP is associated with port 25. A port number is also called a well-known address.
See Packet over SONET.
Power over Ethernet (PoE)
Power over Ethernet (PoE) is a technology for wired Ethernet LANs that allows the electrical current, necessary for the operation of each device, to be carried by the data cables rather than by power cords.
power sourcing equipment (PSE)
Any device that provides power to a Powered Device (PD) in the Power over Ethernet model.
Any device that is powered by Power Sourcing Equipment (PSE) in the Power over Ethernet model.
See Point to Point Protocol.
A means by which security gateway devices authenticate each other. A particular string of bits must be agreed upon by both parties.Related terms: security gateway
An initial set of data preceding a packet. Data bytes all of the form 0xAA and is normally 8 bytes in length.
The size of the preamble.
A 3-bit field that indicates the type of service desired for a packet.
That part of a secure gateway connected to a local LAN, which is presumed to be secure.Related terms: security gateway
A software abstraction within IxANVL that encapsulates the state associated with the processing of an incoming packet.
An IxLoad element, a description of the simulated behavior for Web clients or servers.
A mode of using a network interface card. In this mode, a copy of each packet passing through the network card is available to the process requesting this mode. On many systems, special privileges are required to invoke this mode.
A formal description of a set of rules and conventions that govern how devices on a network exchange information.
protocol data unit (PDU)
OSI term for packet.
protocol independent multicast (PIM)
Multicast routing architecture that allows the addition of IP multicast routing on existing IP networks. PIM is unicast routing protocol independent and can be operated in two modes: dense and sparse.
protocol interface structure (PIF)
A software abstraction within IxANVL that encapsulates the state that is associated with a network layer protocol. A PIF structure exists for each protocol group in the configuration file.
A term used to describe software which generates and decodes packets of a specific protocol family. It is usually modeled after the seven layers of the ISO model.
See Power Sourcing Equipment.
pseudo wire emulation 3 (PWE3)
Refers to the IETF\'s PWE3 (Pseudo Wire Emulation Edge-to-Edge) working group. Luca Martini of Level 3 Communications and a number of other authors have contributed a group of drafts (the Martini drafts) to the PWE3 working group. They define a method to transport a layer 2 protocol across an MPLS network and define how specific layer 2 protocols are encapsulated for MPLS network transport.
A set of repeatable data patterns that exhibits random distributions of bits.
That part of a security gateway connected to a network, which is presumed to be insecure.Related terms: security gateway
public-private key cryptography
A mathematical technique by which two parties generate a pair of related numbers: a private key, and a public key. Each party transmits its public key to the other party. Public-private key cryptography allows each party to independently generate a shared secret that is used to protect communications.Related terms: shared secret
See Quality of Service.
Quality of Service (QoS)
A measure of performance for a transmission system that reflects its transmission quality and service availability. QoS flags are available in IP headers and may be set and measured with the Ixia system.
rapid spanning-tree protocol (RSTP)
An enhancement of the Spanning-Tree Protocol to enable rapid Spanning-Tree reconfiguration capability. This term refers to the IEEE Standard 802.1w-2001 amendment to IEEE Standard 802.1D, 1998 Edition (ISO/IEC 15802-3: 1998) and IEEE Standard 802.1t-2001.
raw network data
Data in the format in which it travels on the physical network.
Remote Defect Indicator. Included as a setting in the K2 byte.
An IxLoad element, as opposed to a simulated server. An actual Web server not simulated by an Ixia port.
The process of restarting a computer. In this document, it refers to the DUT.
An Ixia port’s basic mode of operation – either capture or packet group.
Record Route Object
An RSVP-TE option that requests that a complete list of routers be constructed by reverse message transmission.
In the Ixia architecture, a set of related streams.
The process of installing and activating a license. Registration is done using the Ixia Registration Utility (IRU). Registrations can occur online or offline.
A number assigned to a license by the Ixia Registration Server, and sent via e-mail to a Lab Manager. It is coupled with a registration password.
A password assigned to a license by the Ixia Registration Server, and sent via e-mail to a Lab Manager. It is coupled with a registration number.
The central Ixia server that grants license registration numbers and passwords.
remote monitoring (RMON)
MIB agent specification described in RFC 1271 that defines functions for the remote monitoring of networked devices. The RMON specification provides numerous monitoring, problem detection, and reporting capabilities.
request for comments (RFC)
In the Internet community, these documents specify protocols. They are developed by the IETF.
request reverse option
An RSVP-TE option that requests that a complete list of routers be constructed by reverse message transmission.
resource reservation protocol (RSVP)
Protocol that supports the reservation of resources across an IP network. Applications running on IP end systems can use RSVP to indicate to other nodes the nature (bandwidth, jitter, maximum burst, and so on) of the packet streams they want to receive. RSVP depends on IPv6.
resource reservation protocol--traffic engineering (RSVP-TE)
A subset of the entire RSVP protocol related to Traffic Engineering (TE). This protocol implements an assignment of labels from ingress to egress routers, with consideration for bandwidth and other QoS requirements.
The party in an IKE negotiation that receives a Phase 1 or Phase 2 negotiation request. As opposed to an initiator.Related terms: initiator, Phase 1, Phase 2
Ring APS signalling provides protection switching for bi-directional line-switched rings. Ixia cards do not perform any Automatic Protection Switching between Ixia cards. APS may be forced on the cards under test by modifying the K1/K2 bytes sent from the Ixia port.
Routing Information Protocol. The Internet gateway protocol supplied with UNIX BSD systems. The most common IGP in the Internet. RIP uses hop count as a routing metric.
Routing Information Protocol - Next Generation, for use with IPv6.
An Ixia technique by which packets are reflected back to their source and the round trip time measured.
A path from one network element to another.
A device that is connected to more than one network and is responsible for forwarding packets from one to another.
In routing protocols, a unique number associated with the router. Often one of its IP addresses.
routing information protocol (RIP)
The Internet gateway protocol supplied with UNIX BSD systems. The most common IGP in the Internet. RIP uses hop count as a routing metric.
routing information protocol next generation (RIPng)
Routing Information Protocol – Next Generation, for use with IPv6.
routing update message
A type of packet that contains new routing information.
See Record Route Object.
See Resource Reservation Protocol - Traffic Engineering.
See Security Association.Related terms: security association
The time that an SA is valid. End-points generally attempt to negotiate new SAS before their old ones expire.Related terms: security association
The mechanism by which IxANVL uses external commands to configure the DUT remotely from the IxANVL workstation.
An Ixia tool for generating Tcl setup scripts from active port configurations.
An Ixia tool used to support the use of available test packages. A test package is available for testing server load balancing switches.
Software Development Kit. See Application Programming Interface.
A particular type of BIP errors found or inserted in POS systems.
Secure Key Exchange Mechanism for Internet (SKEME)
Describes a versatile key exchange technique that provides anonymity, reputability, and quick key refreshment.
A network segment terminated on both ends by security gateway devices using IPSec to protect network traffic.Related terms: IPSec, security gateway
TestRelated terms: IP Security
security association (SA)
A data item that describes the authentication and encryption methods and shared secret used to connect two IKE or IPSec end-points.Related terms: IPSec, shared secret
A network device that implements IKE and IPSec on behalf of hosts that do not run these protocols. Pairs of security gateways form one or more secure tunnels.Related terms: IPSec, secure tunnel
A host acting to respond to processing requests. In IxLoad, a Web server.
A set of servers delivering the same information content.
server load balancing
A set of tests for SLB switches, which route incoming traffic to servers in a server farm.
service advertising protocol (SAP)
IPX protocol that provides a means of informing network clients, by means of routers and servers, of available network resources and services.
See Severely Errored Seconds.
A connection between a Web client and server, which may support multiple requests and responses.
severely errored seconds (SES)
For PoS received traffic, the number of one-second periods which contain 30% errored blocks or at least one defect.
See Start Field Descriptor.
The SHA (Secure Hash Algorithm) family is a set of related cryptographic hash functions. The most commonly used function in the family, SHA-1, is employed in a large variety of popular security applications and protocols, including TLS, SSL, PGP, SSH, S/MIME, and IPSec. SHA-1 is considered to be the successor to MD5, an earlier, widely-used hash function. The SHA algorithms were designed by the National Security Agency (NSA) and published as a U.S. govemment standard.
A value produced by the use of public-private key cryptography and used to protect IKE communications.Related terms: public-private key cryptography
simple network management protocol (SNMP)
A protocol used to monitor gateways and the networks to which they attach.
simple network transport protocol (SNTP)
A protocol used by applications to contact a time server, in order to obtain current time-of-day data.
An IxLoad element, a simulation of a client using an intelligent Ixia port.
An IxLoad element, as opposed to a simulated client. A Web server simulated by an intelligent Ixia port.
See Secure Key Exchange Mechanism for Internet.Related terms: Secure Key Exchange Mechanism for Internet
See Server Load Balancing.
In the Ixia architecture, the amount of data saved in a port’s capture buffer, per packet.
IxANVL product that provides the SNMP stack through the core IxANVL framework, allowing users to write their own IxANVL tests (in C code) over SNMP.Related terms: simple network transport protocol
Software Development Kit (SDK)
See Application Programming Interface.
A Data Link Layer field that indicates the MAC level source of the packet.
spanning-tree protocol (STP)
Bridge protocol that uses the spanning-tree algorithm, enabling a learning bridge to dynamically work around loops in a network topology by creating a spanning tree. This term refers to both the IEEE 802.1 Spanning-Tree Protocol standard and the earlier Digital Equipment Corporation Spanning-Tree Protocol upon which it is based.
spatial reuse protocol (SRP)
A Cisco-developed MAC-layer protocol that enables IP routers to be connected directly to optical ring topologies. Interconnecting devices connect directly to fiber via SRP modules without the need for SONET equipment.
See Synchronous Payload Envelope.
For 10/100/1000 Mbps ports, the choice of which speed is selected.
A technique used in RIP routers whereby the RIP router does not absorb received routes into its own routing table.
See Spatial Reuse Protocol.
start field descriptor
A single byte with a value of 0xAD that separates the preamble of a packet from its header.
In the Ixia architecture, a set of transmitted data that consists of a number of bursts, each burst containing a number of packets.
A type of testing that checks the behavior of a device under overload or boundary conditions.
OSPF area that carries a default route, intra-area routes, and interarea routes, but does not carry external routes. Virtual links cannot be configured across a stub area, and they cannot contain an ASBR. Compare with nonstub area and not-so-stubby area.
A TCP packet with the SYN bit set. This is the start of a TCP session establishment.
A TCP packet with the SYN and ACK bit set. This is the acknowledgement from the second part of the start of communications.
synchronous optical network (SONET)
A standard format for transporting a wide range of digital telecommunications services over optical fiber. SONET is characterized by standard line rates, optical interfaces, and signal formats.
synchronous payload envelope
The part of a SONET frame that carries the payload bytes (encapsulated packets, etc.). It also includes the Path Overhead, but not the Section Overhead or Line Overhead.
Short for Tool Command Language. Tcl is an interpreted programming language. Ixia supplies an API to use Tcl in network testing.
Transmission Control Protocol. A connection-oriented transport layer protocol that provides reliable full-duplex data transmission. TCP is part of the TCP/IP protocol stack.
IxANVL product that provides the TCP stack through the core IxANVL framework, allowing the user to write their own IxANVL tests (in C code) over TCP. Available with Tcl extensions.
Traffic Engineering. See RSVP-TE.
A license granted for a limited number of days in the event a valid license is not available.
test assertion list
The list of statements of conformance and non-conformance of a given protocol. Ixia uses this list to develop test methods and tests.
A description of the method of accomplishing a given test. It is expressed in terms of IxANVL actions and the expected DUT responses.
The network which is used to connect the IxANVL node to the DUT.
The collection of tests for a particular protocol.
test suite file
The file containing the test suite function.
test suite function
The C function that contains all the tests in a test suite.
An element of the FIR. See Frame Identity Record.
time to first byte (TTFB)
The time between a client\'s transmission of the last byte of a GET request to the receipt of the first byte of the response from the server.
time to last byte (TTLB)
The time between a client\'s transmission of the last byte of a GET request to the receipt of the last byte of the response from the server.
time to live (IP)
An element of the IP header that indicates how many more hops a packet is allowed to take.
A C function that is scheduled by IxANVL for execution at regular intervals.
Event that occurs when one network device expects to hear from another network device within a specified period of time, but does not. The resulting timeout usually results in a retransmission of information or the dissolving of the session between the two devices.
tool command language (Tcl)
Tcl is an interpreted programming language. Ixia supplies an API to use Tcl in network testing.
See Precedence (IP).
transmission control protocol (TCP)
A connection-oriented transport layer protocol that provides reliable full-duplex data transmission. TCP is part of the TCP/IP protocol stack.
Layer 4 of the OSI reference model. This layer is responsible for reliable network communication between end nodes. The transport layer provides mechanisms for the establishment, maintenance, and termination of virtual circuits, transport fault detection and recovery, and information flow control.
An IKE mode in which the original IP packet is modified by the insertion of an AH or ESP packet. The header of the original packet is not encapsulated.
See Capture Trigger.
See Time to Live (IP).
A tunnel exists between a LAC-LNS pair. The tunnel consists of a control connection and zero or more L2TP sessions. The tunnel carries encapsulated PPP datagrams and control messages between the LAC and the LNS.
In RSVP-TE, an identification of a flow within a LSP (Label Switched Path).
An IKE mode in which the original IP packet is modified by the insertion of an AH and/or ESP packet. The header of the original packet is encapsulated.
An ordered set. In the context of network protocols, it refers to a repetitive sub-structure within the data portion of a packet. For example, a routing update packet may contain multiple tuples, one for each advertised route.
A generic type of many Ixia modules with limited capabilities.
See Unavailable Seconds.
See User Defined Fields.
User Datagram Protocol. A connectionless transport layer protocol in the TCP/IP protocol stack. UDP is a simple protocol that exchanges datagrams without acknowledgments or guaranteed delivery, requiring that error processing and retransmission be handled by other protocols. UDP is defined in RFC 768.
See User Defined Statistics.
During PoS data reception, the seconds during which the block state was in an unavailable condition; generally an error condition within the last 10 seconds.
Communication between a single sender and a single receiver over a network.
universal serial bus (USB)
USB is a plug and play interface between a computer and add-on devices (such as audio players, joysticks, keyboards, telephones, scanners, and printers). The USB peripheral bus standard was developed by Compaq, IBM, DEC, Intel, Microsoft, NEC, and Northern Telecom and the technology is available without charge for all computer and device vendors.
The process of renewing a license to match new version of software. Updates are done using the Ixia Registration Utility (IRU). License updates can occur online or offline.
The address of a file (resource) accessible on the Internet.
See Universal Serial Bus.
user datagram protocol (UDP)
A connectionless transport layer protocol in the TCP/IP protocol stack. UDP is a simple protocol that exchanges datagrams without acknowledgments or guaranteed delivery, requiring that error processing and retransmission be handled by other protocols. UDP is defined in RFC 768.
user defined fields
In the Ixia Architecture, one of four 32-bit counters which can be configured in a number of ways in order to generate data patterns within packets.
user defined statistics
In the Ixia architecture, the ability of the user to define up to four statistics based on packet contents, errors and size.
Van Jacobson (VJ) compression
A compression technique (described in RFC 1144) this is used for low-speed serial links and is specific to TCP/IP datagrams. The compression is similar in spirit to the Thinwire-II protocol (described in RFC 914), but this protocol compresses more effectively and is both efficient and simple to implement.
very short reach (VSR)
Very short reach (VSR) optical transceivers on Ixia OC192c POS ports support 850 nm VSR-1 parallel interfaces for intra-Point of Presence (POP) connections, with a maximum fiber length of up to 300 meters. The OC192c POS serial data stream is modified to be carried by a ribbon cable containing 12 parallel optical fibers.
Virtual LAN (VLAN)
A technique by which a number of nodes on one or more networks form a virtual network.
IxANVL emulation of a device on the test network. The virtual node appears to the DUT as if it were a real device on the network.
virtual private dial-up network (VPDN)
Also known as virtual private dial network. A VPDN is a network that extends remote access to a private network using a shared infrastructure. VPDNs use Layer 2 tunnel technologies (L2F, L2TP, and PPTP) to extend the Layer 2 and higher parts of the network connection from a remote user across an ISP network to a private network. VPDNs are a cost effective method of establishing a long distance, point-to-point connection between remote dial users and a private network.
virtual private network (VPN)
Enables IP traffic to travel securely over a public TCP/IP network by encrypting all traffic from one network to another. A VPN uses “tunneling” to encrypt all information at the IP level.
Virtual LAN. A technique by which a number of nodes on one or more networks form a virtual network.
Very Short Reach (VSR) optical transceivers on Ixia OC192c POS ports support 850 nm VSR-1 parallel interfaces for intra-Point of Presence (POP) connections, with a maximum fiber length of up to 300 meters. The OC192c POS serial data stream is modified to be carried by a ribbon cable containing 12 parallel optical fibers.
Web stress testing
The process of generating large numbers of HTTP GET requests so as to determine the limits of Web servers and load balancing systems.
A sophisticated device which performs Web server load balancing by referring to the contents of Web requests and responses.
A file on the workstation disk that stores the state of an IxExplorer session.
Any computer connected to a local-area network.
A function that wraps another function, usually for converting input arguments or results. IxANVL provides wrapper functions to many of the standard C library functions.
A form of IKE authentication in which identifying information is exchanged according to the X.509 standard. The certificate contains a user\'s public key.
An interface for 10 Gigabit Ethernet, defined in IEEE 802.3ae. XAUI stands for “X” (the Roman numeral for “10”, as in “10 Gigabit”), plus “AUI” or Attachment Unit Interface. The XAUI interface can be used between two optional XGMII Extender sublayers to extend the distance between the XGMII interface and the Physical Coding sublayer to 50 cm – from the standard distance of 7 cm.
The XENPAK Multi-Source Agreement (MSA) defines the standard for pluggable optical transceiver modules supporting 10 Gigabit Ethernet per IEEE 802.3ae. Ixia’s 10 Gigabit Ethernet XENPAK Load Module accepts these transceivers, via an industry standard electrical 70-pin connector.
A 10-Gigabit Small Form-factor Pluggable (XFP) optical transceiver modules that are multi-sourced and intended to be application transparent. Their ultra-small form factor is designed to occupy one-fifth the space and use one-half the power of other transponder modules.
zero-length body message (ZLB message)
A control packet with only an L2TP header. ZLB messages are used for explicitly acknowledging packets on the reliable control channel.
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