Table of Contents

8-Port T1 and E1 IMA Port Adapters

This chapter describes the 8-port T1 and E1 inverse multiplexing over ATM (IMA) port adapter that is supported in the following systems:

This chapter includes the following sections:

Overview of the T1 and E1 IMA Port Adapters

The T1 and E1 inverse multiplexing over ATM (IMA) port adapters use IMA technology to aggregate multiple low-speed links into one larger virtual trunk or IMA group. An inverse multiplexer appears to your ATM switch router as one logical pipe. IMA provides you with modular bandwidth to access the ATM network between T1 or E1 and T3 or E3 rates.

IMA requires inverse multiplexing and demultiplexing of ATM cells in a cyclical fashion among links grouped to form a higher bandwidth logical group with a rate approximately equal to the sum of the individual link rates. The resultant high bandwidth virtual logic group is called an IMA group. You can combine up to a maximum of eight T or E1 lines to form an IMA group.

The T1 and E1 IMA port adapters have eight ports. You can use the eight ports on the T1 or E1 IMA port adapters as independent ATM links or in the IMA mode as follows:

The T1 (1.544 Mbps) and E1 (2.048 Mbps) IMA port adapters provide trunk connectivity and are used for intercampus or wide-area links. Both the T1 and E1 IMA port adapters support UTP connectors.

The T1 and E1 IMA port adapters support up to eight interfaces and therefore must operate with feature card per-flow queuing (FC-PFQ) on the processor card. The T1 and E1 IMA port adapters cannot operate with feature card per-class queuing (FC-PCQ) on the processor card. FC-PCQ and FC-PFQ are two types of daughter cards for the processor card. FC-PCQ provides a subset of the ATM Forum traffic management features provided by FC-PFQ. Refer to the Processor Installation Guide for additional information.

Interface Ports Supported

The ATM switch router supports any port adapter combination required. Table 10-1 identifies the maximum number of T1 and E1 IMA interface ports supported in each system.

Figure 10-1 shows a T1 IMA trunk port adapter that supports UTP connectors.

Figure 10-1   T1 IMA Trunk Port Adapter with UTP Connectors

ATM Connections Supported

The T1 and E1 IMA port adapters provide ATM connectivity to the WAN through T1 and E1 lines. The T1 and E1 IMA port adapters combine up to eight T1 and E1 lines to form a virtual connection with another ATM switch or an edge device such as a router.

The T1 and E1 IMA port adapters allow you to use multiple T1 and E1 lines to connect remote sites with smaller bandwidth requirements to the corporate ATM backbone as shown in Figure 10-2. Using IMA functionality, you can switch data, voice, and video between different remote sites and the central office.

Figure 10-2   T1 and E1 IMA Port Adapter ATM Connections

Note   For IMA functionality, you must connect the ports of the IMA group in both T1 as well as E1 PAMs with another device in the network that supports inverse multiplexing over ATM. If a port is configured as an independent ATM link, you must connect it to another device in the network that supports ATM over T1. The IMA implementation on T1 and E1 IMA port adapter is based on the ATM Forum specification version 1.0 (AF-PHY-0086.000). You must connect the 8-port T1 and E1 IMA port adapters with other IMA devices in the network that are also based on the ATM Forum specification IMA version 1.0.

Regulatory Approvals and Compliances

The T1 IMA port adapter meets the following regulatory approvals:

JATE Approval

The T1 IMA port adapter meets Japan Approvals Institute for Telecommunications Equipment (JATE) approval. See Table 10-2 for JATE approval details for the T1 IMA port adapter.

FCC Part 68 Notice

The T1 IMA port adapter complies with Part 68 of the FCC rules. On the tray of this equipment is a label that contains, among other information, the FCC registration number. If requested, this information must be provided to the telephone company.

This equipment cannot be used on telephone company-provided coin services. Connection to the Party Line Service is subject to state tariffs.

If this equipment causes harm to the telephone network, the telephone company notifies you in advance that temporary discontinuance of service might be required. If advance notice is not practical, the telephone company notifies you as soon as possible. Also, you are advised of your right to file a complaint with the FCC if you believe it is necessary.

The telephone company can make changes in its facilities, equipment, operations, or procedures that could affect the operation of the equipment. If this happens, the telephone company provides advance notice so you can make the necessary modifications to maintain uninterrupted service.

If trouble is experienced with this equipment, please contact us for repair and warranty information. If the trouble is causing harm to the telephone network, the telephone company can request that you remove the equipment from the network until the problem is resolved.

We recommend that you install an AC surge arrestor in the AC outlet to which this device is connected. This is to avoid equipment damage caused by local lightning strikes and other electrical surges.

This equipment uses Uniform Service Order Code (USOC) jacks as shown in Table 10-3.

CS-03 Certification

The T1 IMA port adapter is CS-03 certified. Observe the following general information and safety precautions:

Caution   Do not attempt to make such connections yourself. Contact the appropriate electric inspection authority or electrician as appropriate.

Refer to Table 10-4 for CS-O3 approval details for T1 IMA port adapter.

Cabling the T1 and E1 IMA Port Adapters

This section describes supported cabling configurations for the T1 (1.544-Mbps) and E1 (2.048 Mbps) IMA port adapters, which provide T1 and E1 UTP connections.

All ATM interfaces are full duplex. You must use the appropriate ATM interface cable to connect the ATM UTP port adapter interface with an external
ATM network.

T1 and E1 IMA Port Adapter Supported Interfaces

The T1 and E1 IMA port adapters provide an interface to ATM switching fabrics for transmitting and receiving data at approximately N x 1.544 Mbps and N x 2.048 Mbps bidirectionally for an IMA group on N links. The actual data rate is determined by the physical layer interface module (PLIM). The T1 and E1 IMA port adapters support interfaces that connect to the following physical layers:

T1 and E1 IMA Port Adapter Trunk Connectors

For T1 and E1 trunks, use an RJ-48 connector and UTP cable to connect the T1 and E1 IMA port adapters with the WAN or other switches that support IMA technology. (See Figure 10-3.)

Note   For a description of these connectors, see the "ATM Connection Equipment Requirements" section. (Figure 2-3 shows an RJ-48 connector.)

Figure 10-3   T1 and E1 IMA Trunk Connections and LEDs

If you need E1 75-ohm BNC connections, use the 8-port E1 120-ohm IMA port adapter with an adapter cable as shown in Figure 10-4. Use model number CAB-ADPT-75-120= to order the adapter cable. You need up to eight adapter cables per E1 120-ohm IMA port adapter. You can use straight-through T1 and E1 cables with RJ-45 plugs to connect between the ports on the 8-port E1 120-ohm IMA port adapter and the adapter cable. Use a cable management bracket with 16-F-F BNC connections as shown in Figure 10-4 to organize the cables leading to the spare adapter. Use model number CAB-MGT-16BNC= to order the cable management bracket. For additional information on the 75-120-ohm adapter cable see the "E1, CES E1, DS3, E3, and CDS3 Connections" section.

Figure 10-4   Adapter Cable for E1 75-ohm BNC Connections with a Cable Management Bracket

T1 and E1 IMA Port Adapter LEDs

The LEDs provide status information for the individual T1 and E1 interface connections. The LEDs are shown in Figure 10-3 and described in Table 10-5.