Network Trunk Module
E1 Interface Back Card (BC-E1)
The E1 trunk interface card (BC-E1) provides an E1 trunk interface for the network trunk module (NTM). The BC-E1 connects directly to the NTM and can reside in any rear slot 3 through 8 in an Cisco IGX 8410, 3 through 16 in an Cisco IGX 8420, or 3 through 32 in an Cisco IGX 8430. The BC-E1 provides the following:
•Interfaces to CEPT E1 lines (CCITT G.703 specification)
•Support for both Channel Associated Signalling and Common Channel Signalling
•Support for unframed 32-channel (2.048 Mbps), framed 31 channel (1.984 Mbps), or 30 channel (1.920 Mbps) operation, or any n x 64 Kbps rate down to 256 Kbps
•Configuration of either full or fractional E1 lines
•CRC-4 error checking
•Support for HDB3 (clear channel operation on E1 lines) or AMI
•Passes E1 line events (frame loss, loss of signal, BPV, frame errors, CRC errors, and CRC synchronization loss) to the front card
Detection of loss of packet sync when used with the NTM
120-ohm balanced or 75-ohm balanced or unbalanced physical interfaces
The BC-E1 supports two clock modes. The clock modes are normal clocking and loop timing. You select the mode through software control. With normal clocking, the node uses the receive clock from the network for the incoming data and supplies the transmit clock for outgoing data. The node can use the receive clock to synchronize itself with the network.
With loop timing, the node uses the receive clock from the network for the incoming data and redirects this receive clock to time the transmit data.
Statistics are kept on most line errors and fault conditions, including:
Loss of signal
Frame sync loss
Multi-frame sync loss
CRC errors
Frame slips
Bipolar violations
Frame bit errors
AIS, all-1’s in channel 16 (CAS mode)
Figure 4-24shows and Table 4-18lists status LEDs and connections on the BC-E1 faceplate. When you correlate the table and figure items, read from the top to the bottom.
4-40Cisco IGX 8400 Series Reference
