Configure E3 Interfaces

E3 is a high-speed WAN digital communication technique designed to operate over copper facilities at a rate of 34.368 Mbps. Widely used outside North America, it is the time division multiplexing scheme used to carry 16 E1 circuits. The following standards apply to E3 interfaces:

• ITU-T Recommendation G.703, Physical/electrical characteristics of hierarchical digital interfaces, describes data rates and multiplexing schemes for the E series.
• ITU-T Recommendation G.751, General Aspects of Digital Transmission Systems: Terminal Equipment, describes framing methods.
• ITU-T Recommendation G.775, Loss of Signal (LOS) and Alarm Indication Signal (AIS) Defect Detection and Clearance Criteria, describes alarm reporting methods.

To configure E3-specific physical interface properties, include the e3-options statement at the [edit interfaces interface-name] hierarchy level:

[edit interfaces interface-name]

e3-options { 

    bert-algorithm algorithm; 

    bert-error-rate rate; 

    bert-period seconds; 

    compatibility-mode (digital-link | kentrox | larscom) <subrate value>; 

    fcs (32 | 16);

    idle-cycle-flag value; 

    loopback (local | remote); 

    (payload-scrambler | no-payload-scrambler); 

    start-end-flag value; 

}

You can configure the following E3-specific properties:

• Configure E3 BERT Properties
• Configure the E3 CSU Compatibility Mode
• Configure the E3 Frame Checksum
• Configure the E3 Idle Cycle Flag
• Configure E3 Loopback Capability
• Configure E3 HDLC Payload Scrambling
• Configure the E3 Start End Flags