Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


E1 EOL PICs (M120 Router)

Figure 1: E1 RJ-48 PIC
E1 RJ-48 PIC
Figure 2: E1 Coaxial PIC
E1 Coaxial PIC

Software release

  • Junos OS Release 8.0R2 and later (Type 1)

    End-of-life (see notification PSN-2013-03-891)

Note: These PICs are not supported in Junos OS Release 8.1R1.


  • Four E1 or coaxial ports

  • Power requirement: 0.08 A @ 48 V (3.74 W)

  • Two versions:

    • 4-port, 120-ohm, RJ-48

    • 4-port, 75-ohm, coaxial

  • Onboard DSU functionality for E1 connectivity

Hardware features

  • High-performance throughput on each port at speeds up to 2.048 Mbps, full duplex

  • Maximum transmission units (MTUs) of up to 4500 bytes

  • Per-interface diagnostics and loopback control

  • Per-interface shaping on output

  • Per-interface alarm and event counting and detection

  • HDB3 line coding

  • 4-bit CRC for G.704 framed mode

  • Per-port loop timing

  • Balanced and unbalanced modes

  • Packet buffering, Layer 2 parsing

  • Full bit error rate test (BERT)

Software features

  • Integrated support for G.703 unframed mode and G.704 framed mode with CRC; this feature is user-configurable

    Note: The G.704 implementation supports speeds slower than 2.048 Mbps; multiple channels within a single E1 interface are not supported.

  • Configurable clock source: Internal or loop

  • Encapsulations:

    • High-Level Data Link Control (HDLC)

    • Frame Relay

    • Circuit cross-connect (CCC)

    • Point-to-Point Protocol (PPP)

Cables and connectors

  • Two versions:

    • Four RJ-48 connectors (one per port)

    • Four coaxial connectors

  • Custom 10-ft (3.05-m) posilock to BNC male cable, separate Rx and Tx


One tricolor per port:

  • Off—Not enabled

  • Green—Online with no alarms or failures

  • Yellow—Online with alarms for remote failures

  • Red—Active with a local alarm; router has detected a failure

Alarms, errors, and events

  • Alarm indication signal (AIS)

  • Bipolar violations

  • Excessive zeros

  • Far-end block errors (FEBE, E-bit errors)

  • Loss of frame (LOF), Loss of signal (LOS)

  • Local and remote loopback diagnostics

  • Yellow alarm bit (X-bit) disagreements