Point to Pint Data over G703

[trismegistus]

Hi

Has anyone ever configured point to point links over G703 from a Cisco router?

I don't know the full ins and outs of the scenario, but the user wants to connect three small offices together for data only. They want to use G703 between the sites and I have to confess its something I have never come across.

Any pointers or hints would be welcome. Particularly if anyone knows if I need a signal converter or if they have tried this and it didn't work.

 

[S1ick]

G703 is the interface adaptor between a leased circuit and a router using BNC cables. Looks like you may have to go down the VPN road.

 

[marks66]

I assume you Cisco routers have standard Serial interaces.

In the UK you can request the circuit to be presented on G703,or X.21. However you could also use a G703 to X.21 interface converter.(Not that cheap though)

If you have point to point links the config is very simple.

Router 1
Interface Serial 0
ip address 192.168.0.1 255.255.255.252
no shut
Router 2
Interface Serial 0
ip address 192.168.0.2 255.25.255.252
no shut

You can use un-numberred serial if you like.

 

[routerman]

You would need 2 or 3 E1 circuits for either a star or triangular topology and suitable interfaces on each router. The circuits would be terminated as G703 if thats what your user and provider agree on, but I dont think its that common these days. I normally see X21 presentations (in the UK), you would need to check with the service provider.

S1ick is right, the G703 bit really only describes what type of interface the provider installs, and what sort of cable is neede to wire it up.

G703 links can have G704 framming as well, which splits the 2.048Meg link up into 32 64k timeslots, and this would determine what type of card is fitted in the router.

 

[trismegistus]

Thanks for that evryone.

It turns out the circuit is Telewest Leased Line and they use G703. There were some issues though, namely;

TX and RX labelled the wrong way around by Telewest.

The dual G703 lines were labelled the wrong way around by Telewest ( Site 1 termination labelled Site 2 and vice versa)

So a typical UK telcoms install really then.....