Enterasys Networks X-PeditionTM manual T1 Drop & Insert One-to-One DS0 Bypassing

Features

•Clear Channel service is similar to the full rate service except that the data stream rate is slightly higher because the framing overhead bits are also used to deliver data.

–T3 - Not Available

–E3 - 34.368Mbps payload

T1 Drop & Insert One-to-One DS0 Bypassing

The XSR’s 2-port D&I NIM is designed to cross-connect unused timeslots between the two ports and provide one T1/E1 line for both data and voice traffic, as shown in Figure 4-1. The timeslots carrying data are terminated in the on-board HDLC controller, while voice timeslots bypass the D&I NIM and are terminated in the downstream PBX. This NIM is configured with drop-and-insert-groupand runs identically to the XSR’s 2-port fractional T1/E1 NIM. Show controller t1 s/c/x is useful for debugging the line. Refer to the XSR CLI Reference Guide for associated commands.

Figure 4-1 Drop and Insert NIM Topology

	Voice timeslots
	bypass the XSR	PSTN
	T1-CO
	T1-PBX
	Clock	Frame
PBX	Clock	Relay
	Data timeslots
	terminate in the XSR

The D&I NIM does not support channelized mode nor PRI.

Note: If the XSR loses power, the two T1 lines will be cross-connected by the relays. Consequently, the Central Office will not report the lines down.

Drop and Insert Features

The following features are supported by the D&I NIM:

•The D&I feature allows Channel Associated Signaling (CAS) voice DS0 timeslots to be taken off the Central Office (CO) T1 or E1 interface and inserted into timeslots of the PBX T1 or E1 interface, as long as both interfaces are on the same NIM card.

•You must configure the timeslots belonging to the data channel group. All timeslots not within the data channel group are considered idle and bypassed between the T1 or E1 ports.

•D&I timeslots need not be contiguous - all idle timeslots on both the T1 or E1 interface will be automatically connected and transparently pass voice channels. Idle timeslots are not configured to take part in channel groups.

•The CO T1/E1 and PBX T1/E1 ports are bypassed by relays to maintain a CO-PBX link in case of a power outage or watchdog timeout. So, when the XSR with the D&I NIM is inserted between the PBX and the T1 line of the CO, there is no need to reconfigure the PBX.

4-4 Configuring T1/E1 & T3/E3 Interfaces