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New Member

Splitting a PRI T1

I have a PRI T1 coming to my AS5400. The controller T1 1/0 has the normal setup "pri-group timeslots 1-24"

That creates a Voice port 1/0:0.

What I need are the commends to split those 23 channels in two to be able to have two Voice ports defined.

Any help will be greatly appreciated.

1 ACCEPTED SOLUTION

Accepted Solutions
Silver

Re: Splitting a PRI T1

You can't have multiple D channels, but the following feature might help you -

The customer had two different users and he wanted to split a single T1 PRI service between these users so that one user would use certain B channels and the other user would use different one for outwards calls on the CME router.

The phone company was able to assign these B channel groups with different number ranges for inwards calls.

There is a new feature in 12.4 code that allows you to define individual timeslots of the PRI and assign them to different trunk groups. These trunk groups can be used instead of a voice port in a POTS dial peer, so you can direct calls to very specific B channels on the PRI. Following is a config that demonstrates this feature on an E1 interface (30 B channels - same concept applies for a T1).

!

controller E1 1/0

pri-group timeslots 1-31

trunk-group Customer1 timeslots 1-10

trunk-group Customer2 timeslots 11-20

trunk-group Customer3 timeslots 21-30

!

!

dial-peer voice 1 pots

description - enable DID on group 1

incoming called-number .

direct-inward-dial

trunkgroup Customer1

!

dial-peer voice 2 pots

description - enable DID on group 2

incoming called-number .

direct-inward-dial

trunkgroup Customer2

!

dial-peer voice 3 pots

description - enable DID on group 3

incoming called-number .

direct-inward-dial

trunkgroup Customer3

!

!

dial-peer voice 5500 pots

trunkgroup Customer1

description - Customer 1 : access code 771

destination-pattern 771

!

dial-peer voice 5501 pots

trunkgroup Customer2

description - Customer 2 : access code 772

destination-pattern 772

!

dial-peer voice 5502 pots

trunkgroup Customer3

description - Customer 3 : access code 773

destination-pattern 773

!

In this case, Customer1 users would dial 771 as an access code, Customer2 would dial 772 and Customer3 would dial 773. These access codes would 'steer' the call to the appropriate timeslots on the PRI.

4 REPLIES
Silver

Re: Splitting a PRI T1

Cisco routers can split an incoming PRI into a PRI-group and a channel-group. A serial interface will be created for each of the two groups. The PRI's serial channel carries the D-channel signaling info to/from the telco. The channel-group's serial interface is configured as needed and data traffic into the channel-group can be routed to destinations as needed.

All three solutions (CSU/DSU, PBX configuration, Cisco router configuration) require agreement with the telco how the incoming T1 will be used and what channels will be used for what purposes.

The following document can help you in providing more information ,

http://www.cisco.com/univercd/cc/td/doc/product/software/ios113ed/113ed_cr/dial_c/dcprt1/dcchant.htm

Cisco Employee

Re: Splitting a PRI T1

You can't do that with a PRI on the gateway. it's not supported and there are n plans to change that functionality:

mssol-5400-74a(config-controller)#pri-group timeslots 1-12

mssol-5400-74a(config-controller)#pr

mssol-5400-74a(config-controller)#pri-group ti

mssol-5400-74a(config-controller)#pri-group timeslots 13-24

%The Primary-group is already defined

%The first definition of the primary-group must be removed

before the primary-group can be redefined

You can do it with CAS signalling (that is defining multiple dso-groups) though.

What is the need for multiple dial-peers?

Silver

Re: Splitting a PRI T1

You can't have multiple D channels, but the following feature might help you -

The customer had two different users and he wanted to split a single T1 PRI service between these users so that one user would use certain B channels and the other user would use different one for outwards calls on the CME router.

The phone company was able to assign these B channel groups with different number ranges for inwards calls.

There is a new feature in 12.4 code that allows you to define individual timeslots of the PRI and assign them to different trunk groups. These trunk groups can be used instead of a voice port in a POTS dial peer, so you can direct calls to very specific B channels on the PRI. Following is a config that demonstrates this feature on an E1 interface (30 B channels - same concept applies for a T1).

!

controller E1 1/0

pri-group timeslots 1-31

trunk-group Customer1 timeslots 1-10

trunk-group Customer2 timeslots 11-20

trunk-group Customer3 timeslots 21-30

!

!

dial-peer voice 1 pots

description - enable DID on group 1

incoming called-number .

direct-inward-dial

trunkgroup Customer1

!

dial-peer voice 2 pots

description - enable DID on group 2

incoming called-number .

direct-inward-dial

trunkgroup Customer2

!

dial-peer voice 3 pots

description - enable DID on group 3

incoming called-number .

direct-inward-dial

trunkgroup Customer3

!

!

dial-peer voice 5500 pots

trunkgroup Customer1

description - Customer 1 : access code 771

destination-pattern 771

!

dial-peer voice 5501 pots

trunkgroup Customer2

description - Customer 2 : access code 772

destination-pattern 772

!

dial-peer voice 5502 pots

trunkgroup Customer3

description - Customer 3 : access code 773

destination-pattern 773

!

In this case, Customer1 users would dial 771 as an access code, Customer2 would dial 772 and Customer3 would dial 773. These access codes would 'steer' the call to the appropriate timeslots on the PRI.

New Member

Re: Splitting a PRI T1

Hi pacameron.

Thank you very much for your answer. It allows me to have what I needed. Is a beautiful workaround using a very new feature.

Regards

Vilaro

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