ASR9K and ASR99K BNG

[Peyman Zadmehr]

Hi

As I understood the main difference between ASR9K and ASR99k is SCB Module. This simply means Fabric of ASR99K is provided by a dedicated module. 

Regarding BNG feature, Is the model of SCB has any impact on Number of PPPoE Sessions on Amount of traffic which the box can handle?

For example According to information of this forum, Since 2017, starting IOS XR version 6 ASR9K and ASR99K can provide 512K of PPPoE session on the chassis. There are some limitations on the Card for example 24x10GE supports up to 128K PPPoE sessions since it uses Typhoon NPU.

If we use SCB1(The end of life Fabric module) then Will there be any limitation?

Thank you

Peyman....

[fcuiller]

Hi

BNG feature/PPPoE termination is not handled by ASR 9000/9900 fabric cards. Therefore, your PPPoE scale will not be dependent of number of fabric cards installed in the chassis or their version.

Fabric Cards however play a role in the forwarding architecture of an ASR 9000/9900 router. If you don't have enough FC installed in your chassis, you might lack redundancy and impact traffic in case of FC failure. Also, depending your ASR9900 chassis, you might not be able to achieve linerate performance if there is not enough FC to connect the linecards together.

Recommendation is to have highest number of FC in a chassis to avoid those cases.

Last, make sure you use -SE version of linecards and RSP/RP. Don't forget also to install the IOS-XR BNG package.

You can review following document for more information about ASR 9900 fabric: https://www.cisco.com/c/en/us/support/docs/routers/asr-9000-series-aggregation-services-routers/117718-technote-asr9000-00.html

Fred

[Peyman Zadmehr]

Hi

Thank you for your comprehensive answer. I will look into the link you sent. Two more questions:

1- You mentioned to SE version So I must choose SE version of the Line cards as well? Suppose I don't want to use PPPoE over EtherBundle So I will be in LC mode of BNG.

2- Another question: is this choosing between  between LC mode and RP mode done automatically as soon as enabling PPPoE on LACP llink or I Must issue some command? 

Thank you

[fcuiller]

Hi,

You must use SE version of RP/RSP and linecard. See Hardware Requirements from CCO documentation: https://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k-r6-2/bng/configuration/guide/b-bng-cg-asr9000-62x/b-bng-cg-asr9000-62x_chapter_010.html#concept_AFA13EF2B8CF4DE6B4DC5CE0AC4FBBBC

There is no additional command to add to be in RP/RSP or LC mode. As soon as you configure BNG under a Bundle-Ethernet interface (with or without LACP), system will be in RP/RSP mode.

Fred