SH RUN » Home Lab

How to make a T1 loopback

Bill — Thu, 04 Jun 2009 14:46:07 +0000

Sometimes you need a quick and easy way to test a T1 connection on a piece of equipment. For example, you want to make sure that the T1 WIC on your router is working.

To construct a loopback plug, simply take a single RJ45 plug and connect pin 1 to 4 and pin 2 to 5.

How to make a T1 Crossover cable

Bill — Thu, 04 Jun 2009 13:35:47 +0000

In setting up my home lab, one thing that I needed to do was communicate between my routers using the T1 WICs. For the physical cable connection it is necessary to use a T1 Crossover cable. This is really simple to construct. Using standard twisted pair cable and RJ45 ends, make the following connections: pin 1 to 4, 2 to 5, 4 to 1 and 5 to 2. Below is a diagram:

Configuring T1 WICs for a Home lab

Bill — Wed, 03 Jun 2009 14:20:27 +0000

I have a couple of routers as part of my home lab that I am using for my Cisco certification studies. One thing that I wanted to do was connect two routers together via their T1 WICs. There are two things you need to do:

create a T1 crossover to connect the routers
set the clock settings on each routers’ serial interface to simulate the T1

In another post I will put the details of making a T1 crossover cable, here is a simple example of the configuration you need to apply to each routers’ T1 serial interface.

**apply this to router #1**

ip address 192.168.1.1 255.255.255.248
encapsulation ppp
fair-queue
service-module t1 clock source internal
service-module t1 timeslots 1-24 speed 64
service-module t1 framing esf
service-module t1 linecode b8zs
no shut
**apply this to router #2**

ip address 192.168.1.2 255.255.255.248
encapsulation ppp
fair-queue
service-module t1 clock source internal
service-module t1 timeslots 1-24 speed 64
service-module t1 framing esf
service-module t1 linecode b8zs
no shut