data capability for mft-e1 on cisco 1751 and 1760 is supported beginning with 12.2.8(YJ). try to update your IOS and see what happens. please get back with new "impressions".
You can do it using " interface multilink" :http://www.cisco.com/en/US/tech/tk713/tk584/technologies_configuration_example09186a00800a5efa.shtmlBut be aware of the limitations. Take a look at the tables included in the following white paper: http://w...
Because you don't say anything about any routers or any other devices capable of pachet switching, I suppose you carry on your E1 link only analog voice. The previous answers point out a VoIP solution...but in the same time you can use for example 2...