Cisco 1841 with 1T WIC - Config

Posted on 2009-04-04
Last Modified: 2012-06-27

I need help configuring two Cisco 1841.
We have leased a fixed line provided on a V.35 interface, This is something called Digital multiakess in Norway, and it is provided by Telenor. This is a type of connection where you have 1, main access (2mbit), and then you can have many links defined how many (max: 30) 64kbit/s channels you lease to the other location.

I have found this document (only in norwegian) on their web-sites, without managing to understand how to configure:

I now that the provider supplies the clock, and that timeslot 1 and 2 is used to make a 128kbit/s link to another location.

How do I configure the Serial0/0/0 in my routers? (You dont need to think about IP/routing)

Regards Anders
Question by:andoman
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Expert Comment

by:Don Johnston
ID: 24067118
If your router has a V.35 interface then there will be a CSU/DSU between the router and the service (an E1 line in your situation). That device will be configured for clocking, linecode, framing and timeslots. The only thing you have to do on your router's serial interface is configure the encapsulation (if you don't want HDLC), ip address and do a "no shut".

Author Comment

ID: 24077754
Im still stuck on this.
Spoked to telco today, and they told me I have to do something with the timeslots. I can not understand how that is possible, I cant find any examples of configs there this is used. There is a Tellabs CTU-S unit between line and my Cisco Serial 1T card. Connected with a V35MT cable.

My Serial0/0/0 config looks like this:
interface Serial0/0/0
 ip address
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip route cashe-flow

Do I miss something, I have seen some exampls where there are som logical interfaces like Serial0/0/0:12 ?? Do I need some of this to define timeslots used for each link.?

LVL 50

Expert Comment

by:Don Johnston
ID: 24078072
>I cant find any examples of configs there this is used.

And you won't. That has to be configured on the CSU/DSU which (it appears in your case) is an external device (it looks like a modem). They are typically configured using a small keypad and a one or two line LCD display.

If you have an integrated CSU/DSU, then you can configure it from the IOS.


Author Comment

ID: 24087281
In our case ew have a fractional E1 line. I have read sometng about G.704/G.703 witch mention something about timeslots. If my CTU-box(not user configurable)(modem, or what that is) is a CSU/DSU is it impossible to connect this with V.35 to router?

I might have a wrong WIC card, the one I have does not have CSU/DSU.

The Activity-LED on the multipoint side is flashing all time, even thoug no link is establised and no data is transmitted throug the Ethernetports. Is this normal?

List of things that I now:
- I have been told by the provider that I have to use timeslot 1 and 2.
- I have been told by the provider that I only need "special" configuration at multipoint site (headoffice).
- I have a Cisco 1841 (IP-BASE) with WIC Serial 1T.
- My Cisco is connected to a Tellabs 8110 CTU-S with V.35 cable.
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Expert Comment

by:Don Johnston
ID: 24087459
Now we're getting somewhere.

The Telllabs 8110 CTU-S is a CSU/DSU. It will have to be configured to use the timeslots 1-2. You will have to look through the documentation that came with this unit on how to configure it.

According to this PDF file:
The Tellabs 8110 NTU (CTU-S) is configured and monitored with
the Tellabs® 8000 Network Manager. The Tellabs 8110 NTU (CTUS)
does not require any on-site configuration. However, a handheld
VT100 terminal can be connected into the Tellabs 8110 NTU (CTUS)
to obtain the monitoring and status information.

It appears that you either use their provided software to configure it or you can connect a PC and use a generic terminal emulation application (Hyperterm, etc.) to configure it. I can't find any documentation for this unit online so I can't be much help with that.

By the way, you'll also need to know what framing and linecoding your E1 line is using.

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Author Comment

ID: 24151386
Thanks, so far..
I have contacted a IT engeneer to get this up and work. Will post the solution when its ready.

Author Comment

ID: 24334504
I have been told that I need a channelized e1/t1 serial card, to configure for time slots in router. The Tellabs is a unit that the provider has configured, and I am not allowed to reconfigure this. Does channelized e1 card support the V.35 interface?
LVL 50

Accepted Solution

Don Johnston earned 500 total points
ID: 24334667
The v.35 protocol is used for connections BETWEEN a DCE device (CSU/DSU) and a DTE device (Router).

An E1/T1 card IS a CSU/DSU. With this card, the CSU/DSU is inside the router (an internal modem, if you will). You will connect the 128k circuit directly to the router.

You then configure the card for the number of timeslots, framing and line coding.

Author Comment

ID: 24907424
I needed to give ut the whole E1 line. The providers support realy sucked. They doesnt know what they technically have delivered. Im sure I would have got this to work, but it would have taken too long time, and I would probably buy a lot of expensive Cisco hardware that I dont need. Anyway, Thanks for the support, most of my knowledge came from this forum.

Author Closing Comment

ID: 31566547
Thanks for your support, but I have choosen another "newer" solution, based on IPVPN-network.

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