Issues with Call Manager Express and FXO / line voice connection

I wanted to give you all something that I had an issue with Cisco Call Manager Express (CUCME).

I had two things. One is something I just overlooked, namely I used ephone for a SIP phone, and not phone register pool. The other issue I had was with hearing the outside line, when there was a call going on using an FXO module.

For the sake of this guide I will post the entire configuration down below including the debugging steps.


Please note the following. This will show an basic configuration. note the following things

  1. after doing configuration changes for a phone you need to update the profiles and cnf files. use the following (in enabled mode) to configure this:

voice register global
create profile
create cnf-files

2. Resetting the phones you should use the following command:

voice register global

This all need to be done on the Call Manager Express Router


I start with the voice service voip configuration on the Call Manager Express router.

voice service voip
ip address trusted list
ipv4 192.168.XXX.0
allow-connections h323 to h323
allow-connections h323 to sip
allow-connections sip to h323
allow-connections sip to sip
no supplementary-service sip moved-temporarily
no supplementary-service sip refer
no supplementary-service sip handle-replaces
fax protocol t38 version 0 ls-redundancy 0 hs-redundancy 0 fallback none
session transport tcp
registrar server
no call service stop
registration passthrough

This is just a basic configuration, and you shouldn’t adjust here to much from your own basic configuration on your own Call Manager Express router.

Since this configuration is located in the EU it should be good to see if you can configure the codec based on the default in the region, which in this case is a-law. Based on this I make a voice class

voice class codec 1
codec preference 1 g711alaw
codec preference 2 g711ulaw
codec preference 3 g729r8

the voice register global also needs to be configured before you can add any phones and numbers. In this example I have 5 phones and 5 internal numbers

voice register global
mode cme
source-address 192.168.XXX.X port 5060
max-dn 5
max-pool 5
authenticate register
authenticate realm DOMAIN.LOCAL
timezone 23
url directory http://192.168.XXX.X/localdirectory
tftp-path flash:
file text
create profile
template 1

and here we have the  telephony service configuration

conference transfer-pattern
no auto-reg-ephone
max-ephones 5
max-dn 5
ip source-address 192.168.XXX.X port 2000
url directories http://192.168.XXX.X/localdirectory
cnf-file location flash:
cnf-file perphone
time-format 24
date-format dd-mm-yy
max-conferences 8 gain -6
call-park system application
transfer-system full-consult
secondary-dialtone 0
directory last-name-first
directory entry 1 0123456789 name Telephone Example
fac standard
create cnf-files

Phone Configuration

On this Call Manager Express setup we add a number, 100 in this example

voice register dn 1
number 100
name Office1
label Office1 100

Now the configuration, which is based on a Cisco 8821 telephone

voice register pool 1
busy-trigger-per-button 2
id mac 0000.bbbb.ffff
session-transport tcp
type 8821
number 1 dn 1
template 1
voice-class codec 1
username Office1 password somepass

I also added a template for the phone which looks like this:

voice register template 1
exclude em myphoneapp
softkeys hold Newcall Resume
softkeys idle Newcall Redial
softkeys seized Endcall Redial
softkeys connected Confrn Endcall Hold Park Trnsfer

FXO Port configuration

Now here is the Call Manager Express configuration for the FXO port, which is quite simple. I made sure that the phone is currently directly called, but you can use any number here.

voice-port 0/1/0
compand-type a-law
connection plar 100
caller-id enable

The issue

Now we are going to the issue. and this has nothing to do with the FXO voice-port, but more with the service-engine.

If you use zone-member security (This is important!) on the Call Manager Express router then you can fix it using the following.

For example, you use the zone-security as followed.

interface GigabitEthernet0/0/1
ip address 192.168.XXX.X
zone-member security INSIDE

The solution

Because of the zone-member security on the Call Manager Express router, you also need to do it in the Service engine. Since we use the voice-port 0/1/0, it also needs to be the service-engine 0/1/0.

interface Service-Engine0/1/0
zone-member security INSIDE

Once this is done you can hear the complete voice-call be done correctly. And this is all what was needed.

Until next time!

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