Cisco Systems MGX 8230 manual Cesm for T3 and E3 lines, CESM-T3/E3 Features, T3 Interfaces

Chapter 2 Module and Service Descriptions

Frame Relay Service Modules

CESM for T3 and E3 lines

The MGX-CESM-T3/E3 supports unstructured data transfer over a single T3 or E3 physical port at speeds of 44.736 Mbps (T3) or 34.368 Mbps (E3). Only synchronous timing is supported.

MGX-CESM-T3/E3 is a two-card set consisting of a front card and either a T3 back card or an E3 back card. Each back card provides two T3 or E3 ports (each port consisting of two BNC connectors). Only port one is available on the back card when used with the CESM-T3/E3 front card. 1:1 redundancy is supported through a Y-cable on the line module back cards.

•Figure 2-26 on page 2-52is an illustration of the MGX-CESM-T3/E3 front card.

•An illustration of the CESM back card for T3 lines is shown in Figure 2-27 on page 2-53.

•An illustration of the CESM back card for E3 lines is shown in Figure 2-28 on page 2-54.

CESM-T3/E3 Features

CESM cards support circuit emulation services using standards-based adaptation layers over ATM. The CESM-T3E3 uses AAL1 for T3 or E3 unstructured transfer mode operation, per the ATM Forum's Circuit Emulation Specification, Version 2.0:

•Unstructured Support: supports T3/E3 unstructured data transfer.

•Synchronous clocking: synchronous timing mode only supported. Must derive clock from shelf.

•Onboard BERT: BERT support using on board BERT controller. BERT commands executed on T3/E3 card.

•Maximum number of connections: Maximum number of connections is one. In the unstructured mode, one logical port is used to represent the T3/E3 line and one connection is added to the port to emulate the circuit.

•Programmable egress buffer size and CDV tolerance settings are supported for flexible support of jitter and latency requirements.

•Bit count integrity is maintained when AAL1 lost-cell condition is detected.

•The CESM card provides ingress/egress data and signaling trunk conditioning per VC as per ATM Forum CES V2.0.

•T3/E3 CESM cards can be Y-cabled to provide 1:1 hot standby redundancy of the CESM.

•CESM cards are supported by standards-based management tools, including SNMP, TFTP (for configuration/statistics collection), and a command-line interface. The Cisco WAN Manager and CiscoView tools also provide full graphical user interface management support.

T3 Interfaces

•One DSX-3 (44.736 Mbps +/-40 ppm) interfaces with dual female 75-ohm BNC coaxial connectors per port (separate RX and TX)

•B3ZS line coding

•Pulse shape conforming to ANSI T1.102

•T3 bit error rate tester (BERT) and extended loop-up, loop-down pattern generation and verification

•1:1 redundancy with Y-cabling for T3 CESM cards of the same type

•LOS alarm detection/generation support

•Transmitter loop-timed to receiver or synchronized to shelf

	Cisco MGX 8230 Edge Concentrator Installation and Configuration
2-50	Release 1.1.31, Part Number 78-11215-03 Rev. B0, May 2001