What has CME to do with Issabel PBX? If you’d want to connect Cisco phones with a 3:rd party PBX you’ll need to have the MPP firmware on the phones.
To make calls between phones registered with CME and Isabel, you need to create a SIP dial-peer on CME that points to Isabel. You also need to create a SIP trunk on Isabel that points to CME. For Isabel configuration, you should contact an Isabel expert who can help you with that.
dial-peer voice 1 voip
description Outgoing calls to Isabel destination-pattern 168… <<< Pattern matching your Isabel extensions>>>
session protocol sipv2
session target 192.168.1.1 <<< It should be your Isabel server IP>>>
Please note that this is just an example. You need build based on your requirement. Read the below guide.
A little more complete example with inbound and outbound dial peers would be.
voice service voip
ip address trusted list
ipv4 <Isabel IP 1> !add as many as needed
ipv4 <Isabel IP 2>
address-hiding
mode border-element
allow-connections sip to sip
sip
bind control source-interface GigabitEthernet0/0/0
bind media source-interface GigabitEthernet0/0/0
!
voice class uri ISABEL sip
host ipv4:<Isabel IP 1>
host ipv4:<Isabel IP 2>
;add as many line as there are CPE nodes in the Isabel system
!
voice class codec 10 !Check what codecs you can use to the Isabel system
codec preference 1 g711alaw
codec preference 2 g711ulaw
codec preference 3 g722-64
codec preference 4 g729r8
!
voice class e164-pattern-map 2000
description E164 Pattern Map for called number to PSTN
e164 <Numbers on the Isabel system> !add as many as needed
!
voice class server-group 2000
ipv4 <Isabel IP 1> preference 1
ipv4 <Isabel IP 2> preference 2
;add as many line as there are needed for ITSP service
description Outbound calls to PSTN ITSP provider
huntstop 1 resp-code 404
!
voice class sip-options-keepalive 1
description Used for Server Group SIP OPTIONS PING
!
interface GigabitEthernet0/0/1
description Outside IP Address to Isabel
ip address [B.B.B.B] 255.255.255.252 ! Use an IP that matches the connection to the Isabel system
no cdp enable
no shutdown
!
dial-peer voice 100 voip
description Inbound calls from Isabel
session protocol sipv2
incoming uri via ISABEL
voice-class codec 10
voice-class sip bind control source-interface GigabitEthernet0/0/1
voice-class sip bind media source-interface GigabitEthernet0/0/1
dtmf-relay rtp-nte
no vad
!
dial-peer voice 110 voip
description Outbound calls to Isabel
session protocol sipv2
session server-group 2000
destination e164-pattern-map 2000
voice-class codec 10
voice-class sip options-keepalive profile 1
voice-class sip bind control source-interface GigabitEthernet0/0/1
voice-class sip bind media source-interface GigabitEthernet0/0/1
voice-class sip audio forced
dtmf-relay rtp-nte
no vad
