Henry,
We have lots of T1's here and we've had them go down a few times due to problems with the phone company. An ISDN backup is one alternative that could work, although ISDN can be expensive since you normally pay per minute. Another option might be to have a DSL connection and use something like HSRP (Hot Standby Router Protocol, which is a proprietary Cisco solution). What kind of hardware are you using? Does the T1 connect you to the internet, or is it used as a point-to-point to connect to an internal network somewhere?
Chris
Hi chris, We have couple of stores around the town and all are on a t1 with ISDN for backup except for one on ISDN. Some t1 are shared for voice. We use t1 or ISDN to connect to the main store in order to communicate with the main server and get internet connection. Our internet is share with another company. We are currently using a cisco router and some are on some old gandalf bridge (need to take it out) to share connecting within stores. If a sub store's t1 goes down, it looses connection to private network, internet, and main server. The ISDN backup is there so that we can manually set to dial to SBC to get back into the private network. I am thinking of getting rid of the ISDN since it costs us around 30 bucks for just 1 ISDN bri interface if the T1 proves reliable and if there is a cheaper mean. I am looking at the DSL but i wonder it will be able to connect to our private network like how our current ISDN is setup. henry