Modify Cisco License MAC

Posted: May 24, 2012 in Cisco CallManager, CUCM
Tags: , , ,

Cisco used to bind license file to physical MAC address.  Now, it moves to “License MAC”, which is a hash value of multiple system parameters such as NIC speed, NTP, DNS, hostname, etc.

To view the license MAC, you need to install the system first (CUCM, UCCX, CUPS, etc.).  Then use the “show status” command.

This is somehow inconvenient:

1) You cannot get the license file before finishing the installation.

I personally prefer to get everything ready before starting the installation, such as IP address, hostname, password, license file, installation media, etc.  You could run into lots of surprises when trying to get the license file.

2) When the system parameter was changed, the license file yield invalid.

For example, you add/change DNS server settings on the system, which is pretty common during system integration.

It would be better if you could dictate what license MAC the system use.  You may also use some schema like: AABBCCDDEEFF, where AA is the product code, BB is the site code, CC is the node number, DD is the version number, etc.

In the example above, the “License MAC” was changed to “abcdef123456”.

Since you can use whatever License MAC you like, you may:

  • Get the license file before the system was installed
  • Keep using the same license file after system parameters was changed (such as DNS)

To specify the license MAC, you need to have root access to the system.  Then you’ll modify the file /usr/local/bin/base_scripts/  To the bottom of the file, replace the line

FinalString=`expr substr “$SHA1sum” 1 12`



In newer versions, you might have to change the /etc/selinux/config file so that selinux runs in permissive mode.
Reminder: Don’t be evil.  😉 – and be sure to pay it forward!!!
(R) 2012

Cisco 642-416 Test Prep

Posted: May 22, 2012 in Training
Tags: , ,

The determining factor for whether a gateway registers with a TYPE of VOIP-GW or H323-GW relies entirely on the “allow-connections” commands entered under “voice service voip.” Essentially, if your gateway is functioning as an IP-to-IP gateway, it will display H323-GW.

The commands that make or break this:

voice service voip
allow-connections h t h
allow-connections h t s
allow-connections s t h
allow-connections s t s

After adding or removing these, make sure to bounce your gateway registration with the gatekeeper using “no gateway” and “gateway.”

I just verified this. Here is a snapshot without the commands listed above:

HQ-RTR#show gatekeeper endpoints
CallSignalAddr Port RASSignalAddr Port Zone Name Type Flags
————— —– ————— —– ——— —- —– 1720 58978 Spain VOIP-GW
H323-ID: BR2-RTR
Voice Capacity Max.= Avail.= Current.= 0

After adding the commands listed above:

HQ-RTR#show gatekeeper endpoints
CallSignalAddr Port RASSignalAddr Port Zone Name Type Flags
————— —– ————— —– ——— —- —– 1720 50555 Spain H323-GW
H323-ID: BR2-RTR
Voice Capacity Max.= Avail.= Current.= 0

VoIP Basics Reference Sheet

Link  —  Posted: May 21, 2012 in Uncategorized

I was looking into this customer issue where they upgraded from Call manager 4.x to 7.x and almost all users on 7912 phone lost their speed dials.

I checked the phones and CCMUSER page and found that the dials where there but they are not able to access it.

Created a new Softkey template including “AbbrDial” at “off Hook” mode. Reset the phones and asked them to check.

Customer came back saying they cannot see “AbbrDial” Softkey. All settings in Call manager were fine but for some reason they were not able to see the Abbreviated Dial Softkey.

I checked the firmware for 7912 and it was CP7912080003SCCP070409A.

I decided to upgrade the firmware for 7912 to the latest one CP7912080004SCCP080108A. I loaded the new firmware, restarted TFTP, reset the phones and it all started working fine.

Later I came to know that it’s a kind of a bug that if you upgrade from CCM 4.x to 7.x then your 7912 phones will have issues in AbbrDial Softkey. If you come across this issue, upgrade the firmware and you will be good.

I had an interesting scenario where customer logged a case with us regarding their RightFax server not working. Those of you who don’t know what is a RightFax server can read about it here. When you dial the fax number from outside, it reaches the gateway and you hear one ringback and then a fast busy. The call flow was something like this:

0XXXX23422 >>>> Birmingham GW  FXO >>> on CCM we have FXO port with number 3422 >> on CCM there was a RP 3422 with a RL pointing towards an Intercluster trunk to The was the Right Fax server.

I could ping which proved no issues between CCM and Right fax server.

I then opened debug voip ccapi inout and observed the Ringback and fast busy tone which was not very helpful. I then asked the customer if fax calls through any other gateway are working and luckily I found one gateway where they had successful fax calls. I compared the MGCP config on both gateways and found one line missing from this gateway which was not working.

The MGCP commands common to both:
ccm-manager fallback-mgcp
ccm-manager redundant-host BELL
ccm-manager mgcp
no ccm-manager fax protocol cisco
ccm-manager music-on-hold
ccm-manager config server
ccm-manager config


mgcp call-agent MICKEY 2427 service-type mgcp version 0.1
mgcp rtp unreachable timeout 1000 action notify
mgcp modem passthrough voip mode nse
mgcp package-capability rtp-package
mgcp package-capability sst-package
mgcp package-capability pre-package
no mgcp package-capability res-package
no mgcp timer receive-rtcp
mgcp sdp simple
mgcp fax t38 ecm
mgcp bind control source-interface FastEthernet0/0
mgcp bind media source-interface FastEthernet0/0

mgcp profile default!

The command which was missing was this:

mgcp rtp payload-type g726r16 static
I added that command and Fax started working.

CME Paging

Posted: May 14, 2012 in CallManager Express (CME), Features

A paging number can be defined to relay audio pages to a group of designated phones. When a caller dials the paging number (ephone-dn), each idle IP phone that has been configured with the paging number automatically answers using its speakerphone mode. Displays on the phones that answer the page show the caller ID that has been set using the name command under the paging ephone-dn. When the caller finishes speaking the message and hangs up, the phones are returned to their idle states.


Ephone-dn 22  will be paging DN – the number you dial to broadcast – in this case dial “5001” and it will ring all ephones part of this paging group and they will go on speakerphone.

ephone-dn 22
name Paging Shipping
number 5001
paging ip port 2000

These are paging group members, so dialling 5001 will ring these four numbers:

ephone 4
mac-address 0030.94c3.1111
button 1:1 2:2
paging-dn 22 multicast

ephone 8
mac-address 0030.94c3.0bcf
button 1:2
paging-dn 22 multicast

ephone 12
mac-address 0030.94c3.8567
button 1:3
paging-dn 22 multicast

ephone 13
mac-address 0030.94c3.8724
button 1:4
paging-dn 22 multicast

You can also use groups for Paging:

ephone-dn 9
number 7001
name Sales
paging ip port 2000
ephone-dn 11
number 7002
name Accounts
paging ip port 2000
ephone-dn 17
number 7010
name Sales&Acccounts
paging ip port 2000
paging group 9,11