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Configuring T1 Cards
Introduction to T1
Introduction to T1
A T1 line consists of 24 channels. Each channel can transmit and receive data or digitized voice. The line uses framing and signaling to achieve synchronous and reliable transmission. The most common configurations for T1 lines are ISDN Primary Rate Interface (PRI) and nailed (leased) or unchannelized T1, including fractional T1. (For information about provisioning your T1 line for use with the TAOS unit, see Appendix A, “Provisioning the Switch.”)
ISDN PRI
In North America and Japan, a T1/PRI line typically supports 23 B channels and one
D channel. But if
Nailed or unchannelized T1
Unchannelized T1 lines can be used for nailed connections such as to a Frame Relay network. In such cases the configuration is static, and the TAOS unit treats the T1 line as if it were a single connection at a fixed speed, without individual channels.
Typically, when you pay your telephone company for a leased (nailed) line, you pay more for higher bandwidth. Anything in the range of 0bps to 1.544Mbps can be delivered on a T1 line, and provisioned at some 64Kbps fraction of the full T1 bandwidth.
Channelized line-side vs. trunk-side T1
Calls entering the telephone network from the TAOS unit must enter the central office (CO) through an ISDN PRI line. However, calls coming in on a channelized T1 line can enter either on the line side or trunk side. For best results, ensure that the channelized T1 calls enter the switch on the trunk side.
T1 lines that terminate on the line side of the switch undergo an additional
APX 8000/MAX TNT/DSLTNT Physical Interface Configuration Guide |