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Using a vwic-2mft-t1 to connect via 2 T1's

Being a modest rookie (Just a lowly CCNA) here I need a little help and understanding. I need to connect 2 T1 lines to our companies internal network using a 3725 with a vwic-2mft-t1 card. The lines will be used exclusively for data. My understanding of the config is as follows:

The following will create conection with the ISP at a speed of 1544 and a "virtual" serial interface that is configurable:

controller T1 0/0

framing esf

clock source internal

linecode b8zs

channel-group 0 timeslots 1-24 speed 64

The following configures the "virtual" serial interface with the IP address required to talk to the ISP. And sets the encap at PPP.

interface Serial0/0:0

ip address

encapsulation ppp

no shut

Granted I pulled these examples from the Cisco site - A few questions that I have.

Is PPP the typical encap method used over T1 lines? Or is this something I really need to confirm with the ISP?

I assume the "virtual" serial interface will work like any other interface on the router.

Is this example config enough to test the connection after I set a default route?

Thanks again for helping a rookie out.


New Member

Re: Using a vwic-2mft-t1 to connect via 2 T1's

You don't have to use PPP, Cisco has default HDLC if this is just point-to-point application. However if you use PPP, you need to encap PPP at the remote end as well. You may ping the remote end after the circuit set up.

Re: Using a vwic-2mft-t1 to connect via 2 T1's

HDLC is the default encapsulation on serial interfaces. But HDLC is a properietary protocol. Each vendor has its own version of HDLC. So if the provider is not using Cisco equiopment, you will end up in trouble. Usually the ISP tells you what encapsulation to use... or else its always recommended to ask.

Also the VWIC-2MFT-T1 is a voice wic. This vwic was designed for voice, though it can run data circuits too. I have had trouble with configuring two data T1s on the same VWIC. This again depends on the type of NM you are using. Check this link for more details.

I would recommend using a WIC-1DSU-T1 instead.

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