ASR9K / nV Simple Ring Topology - ICL Oversubsciprion and Load Balancing across ICLs

[Jacobo Schneider]

Hello team,

I find myself in the middle of a nV design for a ring topology and I have some concerns since as per XR 5.3 configuration guide neither ICL Bundling nor Satellite Partition are supported for Ring Topology. I would appreciate you can clarify me the following questions:

1) Does the restriction means that I can only use only two (2) 10G ports on a ASR9KV-V2, one for the "east" side and the other for the "west" side in a  nV ring topology? How can I benefit from the four (4) 10G on the ASR9KV-V2 in an nV ring topology without using partition or ICL Bundling?

2) Can I configure more than 10 GigE Satelite ports in a ICL on the hosts? For example is this configuration allowed?

interface Te0/1/0/3
 transceiver permit pid all
 nv
  satellite-fabric-link satellite network
   redundancy
    iccp-group 1
   satellite 100
    remote-ports GigabitEthernet 0/0/0-43
   satellite 200
    remote-ports GigabitEthernet 0/0/0-43

3) In a ring topology, once the active/standby roles are defined, my understanding is that all the traffic from/to the Satellite to the Active will always go through only one ICL, is that correct? Is there any alternative that allows me to engineer the traffic from/to one Satellite to split across the two ICL to/from the Host?

4) What QoS mechanisms are available to handle the Oversubcription across the intermediate ring spans between satellites? My concern is that as we walk through the ring from the more distant satellites to the hosts, the intermediate spans between satellites will carry the aggregate traffic of several satellites and can be very congested.

Thanks in advanced

Jacobo Schneider

[smilstea · Accepted solution]

1. Yes you can only have two links in ring as of right now

2. Yes we support oversubscription

3. We had plans to allow per access port load balancing but that is still a ways off, for now its all traffic from a given satellite will go only to a single host You could have satellite 100 connected to host 1 and going through satellite 101 and 102 in order to get to host 2 all the while satellites 101 and 102 see host 1 as active. Obviously that is not the best design, but it shows that this could be done.

4. Yes that certainly is a concern and we do have inherent QoS on the ICLs but we also have configurable QoS.

Is there a particular reason you need the ring topology? Or might a simple L1 hub and spoke solve your issue as we can use bundles and partitioning.

Sam

[Jacobo Schneider]

Thanks Sam for the responses

The reason for ring topology is that the satellites are geographically separated so we are using DWDM lambdas to form the ring spans over the available fiber.

Regarding the QoS on the ICL, If you can share some links with detailed information about how to configure QoS on the ICLs, the available options and restriction it would be great.

Thanks again

Jacobo

[smilstea · Accepted solution]

Sorry about the delay, these should help:

http://www.cisco.com/c/en/us/support/docs/routers/asr-9000-series-aggregation-services-routers/117699-configure-ASR9K-00.html

http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r5-1/qos/configuration/guide/b_qos_cg51xasr/b_qos_cg51xasr_chapter_0101.html#concept_9401894BF69D4D5589441959E0E037D9

Sam