How to use T1/E1 ?

[alecpun]

If I already had a T1 circuit (with external CSU/DSU) in my office, can I connect to a Cisco router if it only have a serial interface without any T1 controller ? If so, what kind of encapsulation should I set on the router ?

Many thanks

alec

[alecpun]

and also what exactly will be the configuration difference for a router with and without built-in CSU/DSU. Grateful if anyone can post useful link.

[dathaide]

hi

you can configure whatever encapsulation you want. HDLC (default) ppp or frame relay. I assume you have a CSU/DSU then you would need the correct serial cable (smart serial V.35) depending on your cisco interface from the CSU/DSU to your serial port

Make sure you use the same encapsulation on the other end. I would go with either ppp or hdlc as it is fairly easy to configure

int s0/0

ip address

encapsulation ppp

hope this helps

[jamey]

Hello Alec,

What is it you are trying to accomplish?

If you are trying to connect up a remote site to your office via a T1, you'll have to have a CSU (either internal or external) at the remote end.

If you are trying to connect up the two routers in a "back to back" fashion for testing, you can either use CSUs on both ends (they can both be external or internal or even a mix of the two) or you can buy a DTE DCE cable that will connect to the serial ports on the routers without the need of CSUs. (You can get these off of ebay pretty cheap):

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=28033&item=5704349334&rd=1

-HTH