CUCM integration with Legacy PBX

[niterid3r]

Hi All, Currently we are running CUCME in srst mode registered with call manager 9.x using h323 protocol. The site has E1 connection for pstn and a spare e1 slot. We are planning to integrate cucm with legacy pbx via spare e1 port. There are few questions/ confusions i have which i was wondering if someone could answer 1. What cable to use to connect E1 slot on router to pbx?(Can we use rj45 crossover cable) 2. Can we use the e1 trunk by configuring basic isdn signals or it is necessary to use qsig trunk? I understand we will require configuration on cucm for pbx dial plan to point to h323 gateway and configure pots dial peers on gateway and point it to trunk with pbx. Appreciate the help. Regards Niterid3r

[Dragan Ilic]

1. Try on google "e1 cable pinout"... you will find there adequate cabling model

2. you are going to use e1 signaling there sure - just make decision which side will be network and which one is user

3. after that dial plan and H323 gateway config is off course needed - as you mentioned alread

Hope I gave you enough initial information...

BR,

Dragan

[niterid3r]

Thanks Dragon - That does answer most of the questions.

I was wondering if someone has the same setup in the production environment and able to share the sample config?

Thanks.

niterid3r.

[Dragan Ilic]

What type of PBX you have there? There are plenty of docs online for Alcatel, Siemens, Erricson etc...you can use that one for your setup for sure.

BR,
Dragan

[Aman Soi]

Hi,

you can refer the link

http://www.cisco.com/c/en/us/solutions/enterprise/interoperability-portal/networking_solutions_products_genericcontent0900aecd805b561d.html

PIN details

https://supportforums.cisco.com/document/34981/various-pin-outs-used-pots-connections

regds,

aman

[niterid3r]

Thanks Aman and Dragan

We will be using NEC SV8100 PBX

[Aman Soi]

Hi,

What I suggest , u can involve NEC vendor who can let you know whether EPABX supports QSIG/SIP? Thereafter, u can configure Call manager.

regds,

aman

[niterid3r]

Hi Guys,

So things are much clearer now in terms of toplogy

CUCM--h.323--VG---E1trunk----NEC PBX(SV8100)

I understand the CUCM part of the configuration where I have to create route pattern and associate it to route list and then add a route group which has the gateway into the route list. 

Voice gateway is already configured as h.323 gateway and operating call requests to and from pstn.

CUCM Dial plan - 56XX

PBX Dial plan - 61XX

We have a spare E1 slot which I am planning to connect it to NEC PBX with the below config

controller E1 0/2/1
 clock source internal
 pri-group timeslots 1-31
 description ### To NEC PABX ###

interface Serial0/2/1:15

 no ip address
 encapsulation hdlc
 isdn switch-type primary-net5
 isdn protocol-emulate network
 isdn incoming-voice voice

voice-port 0/2/1:15
 cptone AU
 bearer-cap Speech

dial-peer voice 104 pots

 destination-pattern 61..
 port 0/2/1:15
 forward-digits all

dial-peer voice 6001 voip
 destination-pattern 56..
 progress_ind setup enable 3
 session target ipv4:<CUCM IP>
 voice-class codec 100  
 voice-class h323 1
 dtmf-relay rtp-nte h245-signal h245-alphanumeric
 ip qos dscp cs3 signaling
 no vad

voice class codec 100
 codec preference 1 g711alaw
 codec preference 2 g711ulaw
 codec preference 3 g729r8
!
voice class h323 1
  h225 timeout tcp establish 3

So my questions are below

1. Do I need another dial-peer to match an incoming call from PBX or will it match to the existing ports dial-peer 104 for inbound. Let's say someone from PBX with number 6123 calls to 5623 - Will it match 104 as an inbound dial-peer and 6001 as an outbound dial-peer

2. Do i really have to worry about the codec or I am covered with the calls coming from the E1 trunk and the outbound dial-peer to cucm using g7alaw as a preference

Thanks for help in advance. 

[Suresh Hudda]

This seems to be fine. Its good to go for test, if you face any issue then 'debug voip ccapi inout' & debug isdn q931' will help you for fine tunning.

Suresh
 

[niterid3r]

Hi Guys,

CUCM--h.323-->VG--->E1trunk---->NEC PBX=====(ISDN) for external calls

We have a cisco router with one connection to isdn for external calls and one connection to legacy PBX systems. PBX system has its own ISDN for external calls. VG is configured as h.323

We are planning to migrate few phones from PBX to Cisco by ensuring that their numbers are kept same. Internally it woks fine - I have managed to register one of the PBX range extension onto cisco. however the challenge is how to route external calls for these extensions via PBX as I already have a dial-peer configured on my router for external calls pointing to the ISDN on the router. 

[Carlo Poggiarelli]

Hi.

You can play with prefixes.

For example, when a call starts from an IP Phone to a PBX Extension, on CUCM you can apply a prefix that you can strip on VG.

Eg.

Route Pattern 5XXX (PBX Extensions)

Add prefix 7

on VG

dial-peer voice 7 pots

destination-patter 7....

port X/X/X:15

In this way, you can have a dialpeer on VG pinting to 5XXX on CUCM for migrated phones which will result as best match for route to 5XXX.

HTH

Regards

Carlo

[niterid3r]

Hi,

Thanks for your reply. The issue is not for the internal calls but for the external calls as router has an existing isdn and an outbount dialpeer to match external calls. I would like the migrated phones to use pbx isdn rather than an existing isdn on the router. 

CUCM has only one route pattern 0.@ pointing to VG therefore the manipulation has to be done at the router level.

I have a workaround where i can configure a new route pattern with different access code 9.@ and discard predot and prefix some number like 885 and match that on the dialpeer and point it to e1 trunk for pbx. 

In that instance the access code has to be changed which i guess is not acceptable for users. Just wondering if there is any other way of doing it with keeping the acess code same?

[Carlo Poggiarelli]

Hi.

An alternative, could be e dedicated route pattern 0.@ in a different partition.

That partition could be associated with CSS assigned to migrated phones.

In the above route patter, you can apply a further prefix that would be stripped out on VG.

HTH

Regards

Carlo

[niterid3r]

I will give a shot with that. 

We use local route group for every site with one route pattern 0.@

Would that make any difference?

[Carlo Poggiarelli · Accepted solution]

Hi.

No difference. 

The main thing is that you have to replicate that Route Pattern in a different partition.

HTH

Regards

Carlo