[c-nsp] T1 crossconnect best practice?

[Mike Andrews]

We've started getting into some situations where we'd like to sell raw 
point-to-point T1's to customers without Internet access on 'em.  For 
various reasons it's cheaper to run two T1's, one to each end, that come 
back to our central location, and then cross-connect them together, rather 
than run one line end-to-end.  (Don't ask why.)  :)

We could easily do that with a T1 crossover cable between the jacks, but 
we can't monitor the line for errors then...  plus, at some point soon we 
may bring them in on a channelized DS3 which will make that approach a bit 
tricky without a mux.

So we'd like to put 'em on a 7206VXR we have at the central location. 
For now the T1's would be on PA-MC-8T1's but eventually they'll be coming 
into a PA-MC-T3 for cost reasons.

Here's the problem: as far as I can tell, neither card will do TDM 
switching.  PA-MCX-8TE1 isn't an option because other people here hate 
spending money.  So I'm trying to figure out the cleanest way to 
cross-connect them in software in the router.  What's the current best way 
to do this?

My current plan is to run frame-relay encapsulation on the lines and just 
do frame-relay switching.  I've done that before and it definitely works 
as long as they're running something like IP.  I was hoping there was 
something a little more elegant... and transparent, in case they wanted to 
run something non-IP like TDM-based voice.


Mike Andrews  *  mandrews at bit0.com  *  http://www.bit0.com
It's not news, it's Fark.com.                  Carpe cavy!