• Provides inverse multiplexing to transmit a single high-speed data channel over up to four E1 links
  • Data rates from 1.92 Mbps to 7.68 Mbps, with automatic rate fallback
  • Sync data port interfaces: V.35, RS-530, V.36/RS-449, X.21 or HSSI
  • Features Ethernet/Fast Ethernet bridge with VLAN support as DTE interface to connect 10BaseT and 100BaseT LANs and VLANs over E1 services
  • Compensates for differential delays up to 64 msec
  • Built-in BERT (V.52) and remote/local loopbacks



The IMX-4E1 and IMX-4T1 inverse multiplexers transmit a 6/8 Mbps channel over multiple E1 or T1 links. They bridge the gap between E1/T1 and E3/T3, allowing bridges and routers to operate at their fastest rates. They also provide high speed access to SDH/SONET backbones where the only access services available are E1/T1 lines.

The IMX-4E1 and IMX-4T1 provide immediate connection to installed applications. DTE interfaces are V.35, RS-530, X.21 and HSSI. The rate can be any multiple of 1.472 Mbps up to a total of 5.888 Mbps in the IMX-4T1 and any multiple of 1.92 Mbps up to a total of 7.68 Mbps in the IMX-4E1.

The IMX-4E1 and IMX-4T1 have a built-in 10/100 Ethernet bridge with VLAN support for LAN-to-LAN applications over four E1 or four T1 links.

Load sharing over redundant links is performed to improve the resilience of high speed connections. If a T1 or E1 link fails, the communication link still remains open, but at a reduced speed (automatic rate fallback to lower speeds is supported).

Timing options include:
- internal clock: internal oscillator is the source for E1/T1 links
- loopback timing: E1/T1 transmit clock is derived from E1/T1 receive clock
- station clock: source for E1/T1 transmit clock is framed/unframed all 1s or G.703 compatible

Diagnostic loopbacks available include local DTE loopback, local E1/T1 loopback on all links and BERT V.52 through the remote IMX-4E1 and IMX-4T1.

The IMX-4T1 supports T1 network loopback per AT&T 62411 (in-band code activated).

Full statistical diagnostics capability is according to AT&T PUB 54016 for both E1 and T1.

Local control and diagnostics are available via the front panel LCD or via an ASCII terminal. Call out upon alarm and remote Telnet control are also supported.

The IMX-4E1 and IMX-4T1 are compact 1U high standalone units, with optional hardware for mounting in a 19" rack.