Simple E1 Configuration

[andysk]

We are planning to have E1 that will replace our current Leased channel of 128 Kbps (point-to-point). I just wonder how to configure E1 in Cisco Router, since i have no experience in configure E1.
Is that as easy as like in configure Leased channel?
Thanks in advance.

 

[ADB100]

There are a couple of extra elements that need configuring with E1 circuits:

The E1 Controller must be configured for the number of timeslots:

controller E1 1/0
clock source internal
channel-group 0 timeslots 1-31

The Serial interface created by the controller:

interface Serial1/0:0
ip address 10.1.1.1 255.255.255.252


Additionally you need to specify the clocking on the link. This is usually done by providing an external clock to the routers via a QSIG link or something. This is because the internal clocks on the routers are not very accurate, although you can use it if you have nothing else available. One end must provide the clock to the line, the other end must derive the clock from the line:

Master End:

controller E1 1/0
clock source internal
channel-group 0 timeslots 1-31

Slave End:

controller E1 1/0
clock source line primary
channel-group 0 timeslots 1-31


You must get the clocking correct or the link will constantly error. There are a couple of documents on CCO regarding E1 clocking.

Good luck

Andy

 

[andysk]

Thanks ADB100 for your information. I believe controller E1 is something to do with Digitalized E1 (and also i have to invest on E1 Card also).

Anyway, i have successfully setup one of our link to E1 on interface serial, and the command actually very simple.

Master :
Bandwidth 2048
IP Address 10.1.1.1 255.255.255.252

Slave :
Bandwidth 2048
IP Address 10.1.1.2 255.255.255.252

That's it. very simple.

However, another problem appears when i tried to setup the second line, it won't connected (it always generate error "line protocol is down"). I believe this one has something to do with Modem or the link itself. Any suggestion ?

Thanks.

I attached also the show interface s0/1 :
Serial0/1 is up, line protocol is down
Hardware is PowerQUICC Serial
Internet address is 192.168.60.2/30
MTU 1500 bytes, BW 2048 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input never, output 00:00:01, output hang never
Last clearing of "show interface" counters 00:04:33
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1536 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
28 packets output, 672 bytes, 0 underruns
0 output errors, 0 collisions, 9 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions

 

[ADB100]

When you stated E1 link I assumed you had an E1 presentation - i.e. G.703 coaxial or I.421(?) RJ45 and hence you would need the additional controller configuration and clocking etc. What you have I think is a 2048Mbps circuit presented as X.21?

The line protocol down on your other circuit means exactly that - it can't 'see' the remote device or the remote device is not configured properly.

Depending on the hardware you could try a 'show controllers serial 0/1' and see what signals you have present and if there is a clock being received on the circuit.

Other than that I would check the configs look OK, if they do and you can see signals & a clock try a physical loopback test (usually a button on the NTU?).

Andy

 

[andysk]

From Modem A, issue loopback to Modem B, i can see Modem B is responding (by blinking indicator) also i can see at the router B, the interface is up (loop).
On the hand, From Modem B, issue loopback to Modem A, i can see Modem A is also responding, but on the router A, interface is still down.

 

[ADB100]

You should see a loopback message on the console of the router - or at least you should see it when you do a 'show interface'?

Andy

 

[andysk]

I have found the problem, my serial modules are broken due to electrical power shortage (that came from E1 modem).