We currently have a P2P T1 with two 1721 routers. Will be adding another remote office via P2P T1. Understand we will need a second WIC-1DSU-T1 card to the 1721. Looking at installing 1841 with WIC-1DSU-T1-V2 card. Are the 1721 and 1841 WIC cards compatible? Pre Sales Support "thought so".
I have this problem too.