Rerouting calls from a sip trunk

[Eng.AymanSabry]

Dears i need some help in an implementation

I have 3 IP phone systems NEC, 2 CUCMs

NEC, Dubai

1st CUCM Egypt1

2nd CUCM Moroco

1st Problem

NEC has sip trunk to EGYPT1(1st CUCM)

Egypt1 has sip trunk to Moroco (2nd CUCM)

NEC only has 1 license for 1 sip trunk so i can't do sip trunk between NEC ( Dubai ) and Moroco ( 2nd CUCM )

How can i redirect calls from NEC to Moroco ( 2nd CUCM )

2nd Problem

When i try to access Corporate Directory giving me error host not found

[Chris Deren]

1. for problem 1 make sure the Calling Search Spaces assigned to the SIP trunk to NEC has partitions listed that have the Route patterns pointing to CM2 SIP trunks, this way inbound call from NEC would match pattern destined to CM2 and route it.

2. That is typically DNS issue, make sure the FQDN address of your CUCM server can be resolved from your IP phones.

[Eng.AymanSabry]

NEC--->CUCM1--->CUCM2

CUCM1 to call CUCM2 with route pattern 10.XXX

NEC to call CUCM1 with route pattern 6.XXX

Now from NEC to CUCM1 the calling number is 6.XXX

should i do route-pattern 610.XXX and point to CUCM2 ??

[Chris Deren]

Allow NEC to reach 10.XXX destinations we well, so add a route from NEC to CUCM1 to include 10.XXX besides 6.XXX, this way if call arrives as 10XXX it will know to forward it to CUCM2.

[Eng.AymanSabry]

How to add route can you explain me the steps more specific

[Chris Deren]

You need to do that on the NEC side, which I would not know how to do as I mostly work with Cisco.

Alternatively, if you cannot do this on NEC side you can add some logic on CM01 to attempt to identify if the call needs to be resolved locally or go to CM02.  Are the prefixes you listed 06, 10 part of phone extensions or are all extensions 3 digits across both CUCM? Knowing that will allow us to provide potential solution.  

[Eng.AymanSabry]

NEC dial-patterns XXX

CUCM1 dial-patterns XXX

CUCM2 dial-patterns XXX

NEC to call CUCM1 6.XXX

CUCM1 to call CUCM2 10.XXX

What route-pattern i do to let NEC call CUCM2 through CUCM1

[Chris Deren]

So, how do people know to dial 10 in front of the 3 digit extension so that the system can transfer the call to CUCM2?

What is the inbound portion of the NEC SIP trunk configured as on CUCM01? What CSS does it have and how many significant digits is it set to receive? You can post screen shot here.

[Eng.AymanSabry]

from CUCM1 organization view

Route-patterns are like that

7.XXX gateway NEC to call NEC extensions

10.XXX gateway CUCM2 to call CUCM2 extensions

6.XXX is the called number from NEC to CUCM1 and i discard predot to make the calls come right

Now for NEC to call CUCM2 what route-pattern i do ?

CSS are not an issue consider it NONE because CSS will confuse you more :)

[Chris Deren]

Yes, I understand, but you did not provide answers to my questions in regards to how many digits are accepted by CUCM1 from NEC, is it 4 or 5 where does the 6 get stripped?

The idea here depending on where the digit is stripped would be to let users on NEC dial 6XXX for either CUCM1 or CUCM2 and then on CUCM1 if there is an explicit match of the last 3 digits it routes the call to the phone with that DN. otherwise if there is no explicit match it matches a route pattern XXX and sends the call to CUCM2, think of it as sort of default route. Depending on where the 10 is being stripped (on CUCM1 egress or CUCM2 ingress you would potentially need to prefix it at the route pattern as well).  Using CSS/partitions which by the way you should on every deployment of CUCM to prevent all kinds of undesirable routing including infinite loops would provide you with control of applying this "default routing" only for calls arriving from NEC and not dialed directly from other sources.