buying an ISDN WIC for a Cisco router, they have 2 different ISDN adaptors. ISDN BRI U and ISDN BRI S/T. This will connect to a BT wall mounted ISDN socket. Can't work out which one I need. Have trawled the net. Not sure if they do the same thing but one allows to connect via another ISDN device as well or whether one if for use in Europe and one is not. Can anyone help??

thanks

Dom

 

One is american and has the NTU built in, the other is for europe where we tend to have separate NTUs.

...but I can never remember which

"The ISDN U interface is a two-wire interface from the telephone switch that supports full-duplex data transfer over a single pair of wires. The Cisco 811 and 813 ISDN U interface supports the data service unit (DSU) feature that is integrated in the routers.

The ISDN S/T interface is a four-wire interface from the telephone switch that supports full-duplex data transfer over two pairs of wires. Telephone service providers typically provide an ISDN S/T interface. The Cisco 811 and 813 ISDN S/T interface supports the connection to an external DSU, from which you can connect a digital telephone and other network devices."

Its the four wire S/T interface you need

Deano

 

S/T it is. Just checked.

 

**** me you guys reply quick shame your not as quick on CS

BRI U has the internal NTU, while S/T requries an external as per Deanos post

Bang your dead

 

Go Go Go

 

Cheers guys, had done LOTS of searching and was edging towards the S/T but didn't really know why??