[c-nsp] T1 circuits over OC3

[Andy Dills]

On Wed, 29 Sep 2004, RH List Account wrote:

> T1 or frac-T1 connections are a no-go.  I have a few clients who want to get
> off the frame cloud and onto direct T1s.  The telco has no clue on how to
> deliver it so that I can see it, or what config I should be using.

They should use FRASI (Frame Relay to ATM Service Internetworking). You
will not be able to bring them in any other way, to my knowledge.

As far as I know, at least in Verizon territory, this is not part of the
general frame cloud. Additionally, Verizon provisions the ATM pvc such
that you can get a full 1.54meg on layer3 (IIRC, they suggest a PCR of
1900kbps).

Make sure you set your MTU on those interfaces, speaking from experience.
Otherwise, it will use the MTU of the OC3.


It sounds like you may be SOL. These things vary from telco to telco, but
to my knowledge there isn't any way in the world you're going to get those
telcos to essentially provide you with an L3 mux, and I can't see any
other way of mapping a PTP DS1 onto an ATM circuit. (That's why they do
FRASI and frame encaps).

> interface ATM3/0.23 point-to-point
>
> bandwidth 256
>
>  ip address .
>
>  pvc 23/24
>
>   ubr 256
>
>   oam-pvc manage

Hmm...ubr for FRASI? I've only seen vbr-nrt. Do you have problems with
customers not being able to download at their full bandwidth? Perhaps the
reason these customers want to get "off the frame cloud" is because
they're dropping so many incoming cells, due to you not policing their
cell rate, which slaughters your bandwidth?

Andy

---
Andy Dills
Xecunet, Inc.
www.xecu.net
301-682-9972
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