T-1 and ISDN how do they differ?
Their application make them different. A plain (non-channelized) E1/T1 is good as a leased-line, wherein a service provider can transparently carry customer’s packets from one end to another. A channelized E1/T1 and ISDN PRI are good for various n x 64 Kbps applications such as a voice setup running 23 or 30 calls simultaneously, or as an n x 64Kbps backup to the primary WAN link (leased-line or frame-relay, e.g.).
A plain E1/T1 line (non-channelized) can be multiplexed into a SONET/SDH rate to be transported from one city to another. ISDN PRI and channelized E1/T1 need a “switching” facility in service provider network to interact with the customer’s router using Q921 and Q931 messages. So, depending upon the usage, type of interface on customer’s router and the type of equipment in service provider network differs for ISDN PRI and plain E1/T1.
