Nick Voth <[email protected]> wrote: > We have a number of channelized DS3's that are terminating on to a 7206VXR > with the standard old PA-MC-T3 cards. We have a need to deliver ATM based > DS1's out to Adtran DSLAMs in the field. Customers will connect to the > Adtran units via ADSL and their local telco loop and their data is then > aggregated by the Adtran and on to the ATM based T1 coming back to us.
Let me see if I've understood you correctly: you are planning on feeding a whole DSLAM with a single T1? In other words, the aggregated bandwidth usage of all subscribers you are going to serve is going to fit into a single 1.5 Mbps T1? I thought today's spoiled ADSL users demand a heck of a lot more than that... (The latter thought is based on my personal experience of the level of ridicule I get for promoting my beloved SDSL which also maxes out at 1.5 Mbps.) > SO, my question is if we can deliver these circuits to the Adtran units > using the "encapsulation atm-dxi" on each serial interface. I know this > encapsulation is for delivering ATM through an ATM ADSU, but in this > application, does the far end Adtran function as the ADSU or are we missing > something on our end? I invite someone from Cisco to prove me wrong, but my understanding is that "encapsulation atm-dxi" is another term for what's also known as ATM FUNI: http://ifctfvax.Harhan.ORG/OpenWAN/l2conv.html With ATM FUNI aka DXI the line carries HDLC frames which have the AAL5 packets encapsulated in them, so the hardware is still HDLC. True ATM over DS1, OTOH, would mean running actual 53-octet ATM cells over the DS1 bits, which calls for significantly different hardware. I would expect that a DS1 feeding a DSLAM would need to be true ATM, but I'm not familiar with Adtran DSLAMs specifically. (The DSLAMs which I do know want to be fed with DS3 or higher, not DS1, and they do want ATM cells over that DS3, not FUNI or DXI.) HTH, MS _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
