[cisco-bba] IP DSLAM ( Fully Distributed BRAS)

Tarko Tikan tarko at lanparty.ee
Fri Aug 12 14:43:12 EDT 2005


This is somehow related to the topic. I've been looking for nice solution for 
triple-play on adsl2+.

The problem on the market seems to be on the video side. If you want customer 
separation then you'll need to put each dsl port on dslam into separate vlan. 
Problem is, that this solution doesn't scale with multicast and max. 4096 

Another approach seems to be putting all dsl ports into same vlan and do heavy 
firewalling on dslam. This way multicast really gives benefit and you can 
connect more than 4000 customers into dslams->switches->router combo.

Third approach seems to be multiple pvc's per dsl link. Here you terminate 
data pvcs into separate vlans and video pvcs into same vlan. This again gives 
multicast benefits and you also separate IP-STB provisioning and customer 
data traffic. Problem is, that not-so-dumb customer can get into video pvc 
and do some nasty things. And you need special kind of modem with multiple 
pvc>lan-ports mappings or fancy residential gateway (which kinda sucks)

For voice there are lots of voip-gateways for customer home or for putting 
next to dslam (Pannaway has a nice dslam that has SIP integrated).

Anyone have other thoughts/ideas to share? :) Or even better, has anyone 
actually worked with any triple-play-over-adsl service?


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