I want to I-mux 6 Serial T-1's using a Cisco router. The web page is not clear on router requirments. Some links say only a 7500 with certian VIPs support the feature, but other docs picture 7200's. Will a 7206VXR with either and NPE300 or NPE400 I-Mux up to six T-1's usings PPP multi link.