T1 connections

CDelapena2

Hello,

I understand that T1/E1 CAS connections are typically used for data communications on a WIC interface card. However I see "WIC" labeled on modules with serial ports as well as modules with RJ-11 connectors. Are these the same T1 lines just with different connectors? Also, is one likely to see a VWIC module with a serial port and not a RJ-11 port?

Thank you for your insight

ChickenNuggetz

WIC stands for WAN Interface Card. WAN stands for wide-area network. So if you think about it, serial connections and T1 connections are WAN connections. The WIC modules that you see that have RJ-11 connectors are meant for remote router management as well as dial backup for leased lines like T1s. I work in a data center NOC at the moment and have not seen any of our routers have WIC cards like those, even the older 2600 routers.

astorrs

So basically the way it used to work was you had a serial port on a router - either built in like an old 2500 series, or on a 2600 series (and newer) a WIC-1T or 2T (or NM-4T, etc.) - and you would connect it to an external CSU/DSU that was then connected to the T1 line. Basically one of these:


Around the time the 1700/2600 series routers came out they integrated the CSU/DSU into the WIC cards. These use an RJ48 (not RJ11) jack which is the typical way T1/E1/ISDN service is terminated by the telco. I can't imagine you're going to run into a T1 with an external CSU/DSU still in production these days, but you never know.

CDelapena2

This is exactly what I was looking for. Thanks a ton guys.