Technical Documentation

Configuring the JUNOS Software to Support Channel Groups and Time Slots for Channelized E1 PICs

Each Channelized E1 PIC has 10 E1 ports that you can channelize to the NxDS0 level. Each E1 interface has 32 time slots (DS0), in which time slot 0 is reserved. You can combine one or more of these timeslots (DS-0) to create a channel group (NxDS-0). There can be a maximum of 32 channel groups per E1 interface. Thus, you can configure as many as 320 channel groups per PIC (10 ports x 32 channel groups per port).

To specify the DS0 channel group number in the interface name, include a colon (:) as a separator. For example, a Channelized E1 PIC might have the following physical and virtual interfaces:

ds-0/0/0:x

where x is a DS0 channel group ranging from 0 through 23. (See Ranges for Channelized E1 Interfaces Configuration for more information about ranges.)

You can use any of the values within the range available for x; you do not have to configure the links sequentially. The software applies the interface options you configure according to the following rules:

  • You can configure the e1-options statement for channel group 0 only; for example, ds-0/0/0:0.
  • There are no restrictions on changing the default ds0-options.
  • If you delete a configuration you previously committed for channel group 0, the options return to the default values.

To configure the channel groups and time slots for a Channelized E1 interface, include the channel-group and timeslots statements at the [edit chassis fpc slot-number pic pic-number ce1 e1 port-number] hierarchy level:

[edit chassis fpc slot-number pic pic-number ce1 e1 port-number]channel-group channel-number timeslots slot-number;

Note: If you commit the interface name but do not include the [edit chassis] configuration, the Channelized E1 PIC behaves like a standard E1 PIC: none of the DS0 functionality is accessible.

 

Note: The FPC slot range depends on the platform. The maximum range of 0 through 7 applies to M40 routers; for M20 routers, the range is 0 through 3; for M10 routers the range is 0 through 1; for M5 routers, the only applicable value is 0. The Channelized E1 PIC is not supported on M160 routers.

The theoretical maximum number of channel groups possible per PIC is 10 x 24 = 240. This is within the maximum bandwidth available.

There are 32 time slots on an E1 interface. You can designate any combination of time slots for usage.

To use time slots 1 through 10, designate slot-number as in this example:

[edit chassis fpc 1 pic 2 ce1 e1 6]channel-group 3 timeslots 1-10;

To use time slots 1 through 5, time slot 10, and time slot 24, designate slot-number as in this example:

[edit chassis fpc 3 pic 0 ce1 e1 2]channel-group 1 timeslots 1-5,10,24;

Do not include spaces in a list of time slot numbers.

For further information about these interfaces, see the JUNOS Network Interfaces Configuration Guide.


Published: 2010-04-26