[c-nsp] 7200 VXR TDM Bus Crossconnects?

[Robert Boyle]

At 11:15 AM 5/28/2008, you wrote:
>On Sat, May 24, 2008 at 01:44:36PM +0200, ?ukasz Bromirski wrote:
> > VXR indeed added the TDM bus into the 7200 capabilities, which
> > essentially means you can use 'connect' or 'cross-connect' commands in
> > config mode to cross-connect DS0 between various PA/controllers and
> > use DSP farming.
>
>So what cards can make use of it?  And *how* to do it?

Not much and it's pretty useless. Nobody has been able to tell me how 
to do it. We use the cross-connect command all day long to connect 
ATM PVCs from one router to another router and another ATM circuit 
via IP. (simplified ATM-ATM MPLS sort of) For packet based traffic, 
it's easy. For ISDN PRI (clock dependent data) from one interface T3 
to another T1, it doesn't work according to Cisco. If the MIX bus 
doesn't actually use the TDM backplane in the VXR is that just a 
vaporware "feature"? Is anyone using it to do anything? I'm just curious.

Here's more info from Cisco about the MIX bus. It seems like a pretty 
useless feature. Why bother? Just use a crossover T1 cable between 
the two ports without using the router. If you are switching DS0s, 
why? That's only one voice channel and not enough data for anything 
other than maybe an ATM machine or credit card processor or a legacy 
text terminal app? If it can only switch within a single card, it 
isn't using the bus on the VXR. I don't get it. Does anyone else 
understand this more than I do or than the cisco tech below did?

-Robert


From: "Andrea XXXXXXXXX" <xxxxxxxxxx at cisco.com>
To: <robert at tellurian.com>
Subject: SR XXXXXXXXXXX - TDM Bus in VXR
Date: Tue, 27 May 2008 17:55:10 -0600

Hello Robert,

Thank you for your patience. I did a research and in this case the only card
that supports TDM cross connect (or drop and insert) is the PA-MCX-8TE1, and
this feature only works on the ports (controllers) within the same MIX PA
and not between the PAs.
In regards the dial-in modem questions, I would advise you to open a new TAC
case since this technology is handled my a different group of engineers that
will be able to answer your questions in regards the appropriate hardware for
dial-in modem (terminating calls on a PRI).

Best Regards,

Andrea XXXXXXXXX
Cisco TAC Engineer
Multiservice Voice Team
Monday through Thursday 10:00 am - 7:00 pm Eastern Time (GMT-04:00)
Friday 12:00 pm - 9:00 pm Eastern Time (GMT-04:00)




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