TDM channelization and clear channel applications

Overview

When you create a 4 or 12 × DS3/E3 card, 4 or 12 DS3/E3 ports are created. You can then create DS3/E3 channels using the NFM-P, one per port. Each DS3/E3 channel can be channelized into 28 independent DS1 or 21 independent E1 data channels or, in clear channel applications, the DS3 can be the connection termination point. For channelized DS3 connections, each DS1 channel can be channelized to 24 DS0 groups and each E1 channel can be channelized to 31 DS0 groups. To use a DS1 or E1, you must create at least one DS0 group for the DS1 or E1.

By default, DS3 ports are automatically created for clear channel connections. To create a channelized DS3, you must configure the DS3 channel type as E3 or DS3 on the port. To channelize the DS3 to the DS0 level, you must set the Channelization Type to Channelized DS1 or E1. The following figure shows the channelized DS3 port structure for DS1 channels.

Figure 16-3: Channelized 12 × DS3 port structure for DS1 Channels

The channelized DS3 port structure for E1 channels has the following parameter values:

each DS3 port supports 21 E1 channels
each E1 channel supports 31 DS0 channel groups

TDM-based DS3 channelization uses the following syntax:

DS3 channel configured for TDM:

card slot/daughtercard/port.DS3-

DS1 channel from a TDM-based DS3 channel:

slot/daughtercard/port.DS1-[DS3#].[DS1#]

E1 channel from a TDM-based DS3 channel:

slot/daughtercard/port.DS1-[DS3#].[E1#]

DS0 group channel from the DS1 channel:

slot/daughtercard/port.DS0Grp-[STS3#].[STS1#].[DS1#/E1#].[Group#]

The following table provides an example of the naming conventions for a 12 × DS3 port.

Table 16-3: Example of TDM channel naming convention

Syntax	Description	Additional information
Channel 1/1/1.ds3	1/1/1 is the slot number/daughtercard number/port number .ds3 identifies the channel as DS3	Because DS3s are unchannelized by default, you must configure the Channelization Type as Channelized.
Channel 1/1/1.ds1-1.2	.ds1 identifies the channel as DS1 1 is the DS3 number .2 is the DS1 number (1 to 28)	Identifies the DS1 channel and shows how the DS3 level acts as a place holder for the DS1s.
Channel 1/1/1.e1-1.2	.e1 identifies the channel as E1 1 is the DS3 number .2 is the E1 number (1 to 21)	Identifies the E1 channel and shows how the DS3 level acts as a place holder for the E1s.
Channel 1/1/1.ds0Grp-1.2.23	.ds0Grp- identifies the channel as a DS0 group 1 is the DS3 number .2 is the DS1 number (1 to 28) or E1 number (1 to 21) .23 identifies the DS0 channel group (1 to 24) on the DS1 or (2 to 32) on the E1	The DS0 group is configured on the DS1 or E1 channel. Only a DS0 can be used as a CTP.