E1 connection to 2851 router VWIC2 2MFT-T1/E1

[jimeec]

Brussels Belgacom Telco provides the connection with a DNT/2M modem. On the back there is an RJ48/45 hand off labeled G.704/2MB. I am told by Cisco TAC that I need to connect this to my VWIC2 2MFT-T1/E1 in my 2851 router with an ISDN cross over cable but it does not show a link light so I have a layer 1 issue. I tried a straight through cable but still no luck.

Any ideas on what type of cable I should be using? below is the pin out that TAC told me for the ISDN cross over cable that I made.T1/E1 crossover (for PRI and CAS back-to-back connection):
RJ-45 ----- RJ-45
1 ----- 4
2 ----- 5
4 ----- 1
5 ----- 2

 

[whykap]

That is the correct pin out for a T1 x-over cable. You can order one or make one to test your T1.

 

[jimeec]

thanks, I am in Brussels and this is an E1 PRI. The circuit was connected to a nortel pbx and I am trying to move it to the E1 card in the 2851 router to work with call manager. in the US I usually just use a straight through cable from the smart jack to the E1 card and it works fine. Belgacom however drops the circuit off with this modem so I am assuming it comes in as ISDN and is converted in this modem to the E1 signqling with the RJ45 on the back of the modem. They are telling me I need an ISDN cable from there to the router card. someone else told me I need an ISDN 30 cable. Is there a difference between the two cables? I made the cable described with the pin outs here but it doesnt even show a link light when connected?? Any further ideas?

Any info will help and be appreciated as I can not return to the US until I resolve this

Thanks.

 

[whykap]

ok so an ISND 30 pinout cable is as follows:
For a straight cable, use the following:

1-1,2-2,4-4,5-5.

For a crossover cable, use the following:

1-4,2-5,4-1,2-5.


As you see it is the same wiring standard as here in the US.
have you checked with Belgacom to verify that they didn't take the circuit out of service cause they got errors on it? I've seen that happen before.

Have you tried bypassing the modem and go straight into the smartjack and see what happens? I wonder if that modem is converting it to a DSS CAS or something like that.

What's the modem manufacturer and model number?

 

[jimeec]

The modem is a Nokia DNT2m network terminal with Belgacom branding on it. It can be seen here:

http://www.hedindata.se/dokument/dnt2m.pdf

They have it wired directly to a Krone block so I can't take the modem out of the picture. From their dmark on the krone block it has an RJ11 that plugs into the back of the modem and then I am supposed to plug into the RJ48/45 port on the back also that is labeled G.704 and connect it to my gateway card.

For the ISDN 30 cable above are you saying to make a cable where pins 1,2,4,5 are straight through to each end? I think the ISDN 30 is what I need regardless of the fact that Cisco TAC tells me to use an ISDN cross over cable which I made according to what you have above as well and it did not work.

I know the circuit is not disabled at Belgacom because I can swing it back to the PBX and it works fine. I have been swapping it between the pbx and the VOIP gateway card quickly to test so they won't disable it as I have seen that before as well.

Any other advice you can provide would be great and thanks for the help so far!

 

[whykap]

so when you plug it in the VWIC card with either a straight through or a t1 x-over and you stat the controller card it shows as down?
Do you wait long enough for the modem and router to handshake? I know it should happen right away but you never know.
It seems that you have everything correct so I am just reaching here.
have you tried rebooting that Nokia modem while it's plugged in the VWIC?
Again I am just reaching here but I am out of ideas.

 

[jimeec]

I assume when you say straight through T1 and xcross over T1 cable you mean the ISDN30 cables you provided pin outs for above? If true then I have only tried the ISDN cross over cable and I don't even get a link light on the gateway card. however if I use standard ethernet cable which I always use in the US I get a link light but the port shows as down. I will try the straight through ISDN30 cable pin out you provided above and I will also reboot the modem as I have not ried that either. My fear is if I reboot the modem the PRI WILL go down on the Belgacom end and I will have to rely on them to bring it up. they suck. They are the equivelent of Verizon in the US. Too big to worry about an office with one E1.

 

[whykap]

If you are getting a link light with the straight thru then you got the correct cable.
What does the router show when you type
show controller E1 x/x/x

it should show as up. You just need to get the D-channel up after that.

You are on the correct path.

 

[jimeec]

Thanks for all your help. the straight through cable was the correct one to use. Belgacom telco needed to change the framing to unframed to work with my gateway card. I got it all working and was able to fly back to the US before our snowstorm hit.

Thanks again. JimC-