[c-nsp] Bridging multiple inner VLAN's

[Dave Weis]

On 19 January 2012 03:29, Dave Weis <djweis at internetsolver.com> wrote:
>>
>> This might not be possible but seems like it should be somehow. I am trying to find a way to terminate multiple inner vlan's in a single outer vlan into the same bridge domain. The intent is to terminate DSL subscribers that come in via ATM OC3 and then go through an Adtran DSLAM where each VCI is converted to a corresponding inner VLAN tag. For example, VCI 54 = inner VLAN 54. I can set the outer tag number.
>>
>> Looking at the data sheet for the ME3600X/ME380X at http://www.cisco.com/en/US/docs/switches/metro/me3600x_3800x/software/release/12.2_52_ey/configuration/guide/swevc.html suggests that this device may be able to do what I'm trying to do but I'm not familiar with them.
>>
>> Has anyone done something similar?

>I'm not entirely sure if I understand you correctly, but if you strip
>the inner vlan on the ingress how would you know what inner vlan to
>assign to all egress packets that should go towards that internal tag
>of 54? For that to work the device that does the operation would have
>to remember not only the MAC address but also the inner vlan from the
>ingress packets.
>We solved this by making the BRAS interpret double tags and that
>worked well for us.

That's a great question, I would suppose it has to keep a table of MAC to inner tag as they are stripped.

Are you using PPPoE on your BRAS? This is for a legacy setup with 1000+ bridged modems at the far end.

Thanks!
Dave