We're beginning to set up a leased dedicated T1 between two office locations, and we've received in the two 1841 routers w. the WIC 1DSU-T1-V2 card installed. They will be within the company firewall, so IOS firewall would not be as much of an issue.
Only current question now, is of the available IOS versions, which would best suit the situation?
Thanks in advance!
There are at least two aspects to consider when choosing an image to run on a Cisco router such as the 1841. There is a question of what version and there is a question of what feature set. If there are particular functionalities that you need there may be some differences in version, but it sounds like you want a router to do basic packet forwarding so pretty much any version would do what you need. I have a customer with a number of 1841s and we have been running 12.4(15)T1 and been happy with it. In terms of feature set, given what I think I understand about your requirements I would suggest that you get the IP Plus feature set.