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■JUNOS 4.1 and laterSoftware release
■Four T1 ports
■Power requirement: 0.08 A @ 48 V (3.7 W)
■Supports clear channel T1 per port (1.544 Mbps per channel)
■Supports attenuation up to –12 dBm
Description
■Per-port loop timing
■Onboard DSU functionality for T1 connectivity
Hardware features
■ESF and SF framing
■B8ZS and AMI coding
■ESF CSU counters, WRT impairments, and CRC checking
■Local DS1 line loopback, remote line loopback
■Configurable clock source—internal or loop
■Encapsulations:
■High-Level Data Link Control (HDLC)
■Frame Relay
■Circuit cross-connect (CCC)
■Point-to-Point Protocol (PPP)
Software features
■100-ohm RJ-48 connectorCables and connectors
One tricolor per port:
■Off—Not enabled
■Green—Online with no alarms or failures
■Amber—Online with alarms for remote failures
■Red—Active with a local alarm; router has detected a failure
LEDs
■Alarm indication signal (AIS)
■Bipolar violations
■Excessive zeros
■Far-end block errors (FEBE, E-bit errors)
■Loss of frame (LOF), Loss of signal (LOS)
■Yellow alarm bit (X-bit) disagreements
Alarms, errors, and
events
66 ■T1 PIC
M20 Internet Router PIC Guide