[nsp] Terminating ADSLs via ATM PVCs on Cat5000 vs on 7200

Matti Saarinen mjs at cc.tut.fi
Tue Apr 29 16:36:05 EDT 2003


I've been told that it would be wiser to terminate ADSL connections,
which are transmitted over ATM PVCs, on 7200 and use RBE than to
terminate them on Cat5000's ATM card and bind the PVCs to VLANs.

Currently we have a setup where the PVCs terminate on Cat5000 and
there they are bound to different VLANs. Every VLAN is then
transported via a dot1q trunk to another switch(es) and eventually to
router inteface. This works. 

So, the ATM card's config looks like this:

interface ATM0.14 multipoint
 atm pvc 69 0 69 aal5snap
 atm pvc 70 0 70 aal5snap
 atm bind pvc vlan 69 65 
 atm bind pvc vlan 70 65 

!
interface ATM0.15 multipoint
 atm pvc 66 0 66 aal5snap
 atm pvc 67 0 67 aal5snap
 atm bind pvc vlan 66 29 
 atm bind pvc vlan 67 29 


( I know that the switch cannot switch packet coming from PVC 0/66 to
  PVC 0/67, for example. The config has some historical oddities.)



Now, the buffers on the Cat's ATM card are not very large which may be
a problem. Also, the box starts to be expensive to keep under service
contract. Therefore it would be nice to move the ADSL termination
process to some other equipment and a 7200 would be an alternative.

Can I build a similar setup with 7200? I mean the 7200 would just
collect the PVCs transporting the ADSL connections and bridge them to
ethernet VLANs. The routing process would take place on some other
box.


Cheers,


-- 
- Matti -


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