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VWIC-2MFT-T1-DI capabilities

I'm trying to understand the capabilities of this card, and am lacking in some knowledge of the telephony aspect.

If the T1 I present to this card has PRI signaling, can the D&I functionality allow me to hand, say, half the channels to an otherwise voice-capable router like "controller T1 n/n/n, pri-group 1-12, etc." and then treat the other half as a standard serial frame-relay connection, e.g. "int Se n/n/n.nnn point-to-point"?

In an alternative application, same card, same T1, same signaling, can I take half the channels out of the second port in the card and hand them to a legacy PBX? And keep the PRI signaling?

Thanks for the anticipated help.

Hall of Fame Super Gold

Re: VWIC-2MFT-T1-DI capabilities


in theory, yes you can do both things. But in practice, you will find application with "partial PRI" and "partial data" do not exist. What is more common, is that you have T1 CAS voice for some timeslots, and data for the others.

In other words, when there is PRI, most PBX will assume that the entire T1 is dedicated to this.

Hope this helps, please rate post if it does!

Community Member

Re: VWIC-2MFT-T1-DI capabilities

Thank you for your reply. However, what if the "PBX" is the 3845 router which I'm installing the VWIC-2MFT-T1-DI into? This box _already_ terminates one full voice PRI, using a VWIC-1MFT-T1.

Hall of Fame Super Gold

Re: VWIC-2MFT-T1-DI capabilities

Ok, can you make on example of how would you use the new two-port card ?

Keep in mind, in PRI D-channel is always timeslots 23, so any data timeslot (ds0-group) would be allocated from 22 and below.

I have never seen such a configuration in practice although it should work in theory.

Community Member

Re: VWIC-2MFT-T1-DI capabilities

OK, say we have a 38x5 router, currently with a VWIC-1MFT-T1 terminating a voice PRI, like this:

controller T1 0/1/0

framing esf

linecode b8zs

pri-group timeslots 1-24 service mgcp

and a WIC-1DSU-T1 terminating a full T1 frame-relay circuit for data, like this:

interface Serial0/0/0

description Connected to Qwest Frame Relay T1

no ip address

encapsulation frame-relay IETF

no fair-queue

frame-relay traffic-shaping

frame-relay lmi-type cisco


interface Serial0/0/0.100 point-to-point

description Qwest to home office

ip address nnn.nnn.nnn.nnn

ip pim sparse-mode

frame-relay interface-dlci 100 IETF

What I want to do, in essence, is to take half that frame T1 and add it to the voice pool. What I'm hoping I can do is to replace the WIC-1DSU-T1 with a VWIC-2MFT-T1-DI (reconfigure the circuit with the carrier as PRI signaling, if necessary), treat 11 or 12 channels of it as frame-relay data and take the other 11 or 12 and add them as PRI to the voice pool. I think (but am not sure) I can do more or less the same with an external D&I mux/CSU.

Hall of Fame Super Gold

Re: VWIC-2MFT-T1-DI capabilities


In other words, you want a 640 kbps (10 x 64) data circuit, and the rest a voice channel / PRI, on a single T1 line. As I said the router should be able to do that, even with the "non-DI" version fo VWIC2, but you have to ask your provider of FR and PRI if they are able to mux both services on a single T1. Sometime this called "integrated access".

Hope this helps, pleas rate post if it does

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