Daisy-Yuanwen Sun
Principle Technical Product Manager

Ixia Demonstrated Successful SRv6 Tests at EANTC Interop 2020

April 27, 2020 by Yuanwen (Daisy) Sun

Last month, Keysight's Ixia business participated in a multi-vendor interoperability test event, hosted by European Advanced Networking Test Center (EANTC), held in Berlin Germany. This event is an annual event to showcase industry readiness of advanced networking technologies and promote interoperability among vendors to create better ecosystems for the end-user community. 

Even with the impact of COVID-19 and travel restriction, the interop test was held as scheduled with multiple vendors joining remotely and working together with onsite participants. Thanks to the EANTC and participant vendor teams who put in the extra effort to manage remote participation and work at shifted hours with great cooperation to make this interop test event successful.

We participate in the event every year along with many key vendors and have tested extensively in the areas of Ethernet virtual private network (EVPN), segment routing (SR) and software-defined network (SDN). We decided to focus our effort on SRv6 and SDN testing this year. Refer to the EANTC published whitepaper for complete test cases and results.


Keysight’s Ixia test gear used in the EANTC 2020 interop included IxNetwork, Ixia XGS2 chassis with Novus load modules

Throughout the two-week event, we have worked with multiple vendors and successfully finished more than ten test cases and combinations in the following areas: 

  • L3VPN over SRv6
  • EVPN VPWS over SRv6
  • EVPN VPLS over SRv6
  • SRv6 TI-LFA
  • L3VPN over SR MPLS
  • BGP egress peer engineering with SR
  • Seamless BFD over SR-TE tunnel
  • BGP Flowspec for IPv6

Such interops provide a diverse environment where we can “test the tester” — ensuring that the IxNetwork L2/3 test solution interoperates well with all the vendor implementations. But beyond this, I want to share a few segment routing observations  that came from our testing this year.

Segment Routing MPLS 

SR MPLS technology is now matured. With rapid specification updates in the past couple of years, the IETF Spring working group has ratified most of the SR MPLS protocol specifications to the RFC stage. During hot-stage testing, many vendors joined the SR MPLS test cases and there was no major issue observed. This further confirms the maturity of the technology and the industry readiness. 

One interesting note is on label space: some vendors had restrictions on which MPLS label range can be used for SR labels. This may make it difficult to support common SR global block (SRGB) ranges in multi-vendor scenarios. Though different SRGB ranges do not impact proper SR operation, it may cause complexity in troubleshooting.

Segment Routing v6

SRv6 is relatively new compared to SR MPLS and the specifications are still evolving. We do see increased support from vendors compared to the previous year. There were six vendors participating in the SRv6 test cases this year. These test cases were also more extensive than last year. We tested all major areas including ISIS SRv6 underlay, L3VPN and EVPN services, and topology independent loop free alternative (TI-LFA). Please watch the following SRv6 TE & TI-LFA demo for more details on one example of the SRv6 test execution.

There were a few interop issues encountered during the hot-stage worth mentioning, characterized by differences in the draft version and multi-topologies (MT) supported. 

  1. Different draft-version support sometimes lacks backward compatibility. Minor differences were seen in packet formats of BGP update messages. One vendor was able to upgrade the draft support quickly and the interop issue is resolved after that.
  2. Different multi-topology support in SRv6, where one vendor does not support both multi-topologies 0 and 2 for ISIS SRv6, caused interop problems. All nodes in the network should support a common MT, otherwise reachability issues may arise in the network. 

SRv6 is a promising technology for next-gen programmable network infrastructure. There are many use cases that can benefit from the SRv6 network programming concept, such as those enabled by 5G. It is exciting to see increased vendor support and good interoperability results. We anticipate that SRv6 will not be far from being ready for prime time in the next couple of years.

As a test tool provider, Keysight always strives to stay on top of cutting edge technologies to help our customers with early validation and deployment. It has been a valuable experience to test out our new technology offerings with key vendors in the industry, learn of use cases from different perspectives, and witness the successful interop and industry readiness. This helps us to provide better solutions to our customers in dynamic markets with unique offerings. As always, customer success brings our success.

For more information, please visit the IxNetwork product page.