Supporting Auto Registration and Auto Assignment of IP Phones

Since its 4.0 version, CME has supported auto-registration of Cisco IP phones by default. This allows IP phones with no ephone configuration in the CME running configuration to automatically register with the CME router. The CME router does not automatically create an ephone entry in the running configuration; however, the registered phones can be verified by using the show ephone command, as shown in Example 5.24.

Example 5.24 Auto-Registered Ephone Verification

CME_Voice# show ephone

ephone-1 Mac:0014.1C48.E71A TCP and Server in ver 8

socket:[3] activeLine:(


SCCP ver


mediaActive:0 offhook:0 ringing

0 reset:0 reset_sent:0

paging 0 debug

0 caps:8

IP: 52850 Telecaster 7960 keepalive 277 max_line 6

button 1: dn 10 number 1010 CH1

IDLE overlay

button 2: expand-line 1 (DN -1


button 3: expand-line 1 (DN -1


overlay 1: 10(1010) 11(1010)

phone has expansion line(s)

ephone-2 Mac:0019.D122.DCF3 TCP and Server in ver 8

socket:[5] activeLine:(


SCCP ver


mediaActive:0 offhook:0 ringing

0 reset:0 reset_sent:0

paging 0 debug

0 caps:7

IP: 50645 CIPC keepalive 0 max_line 8

ephone-3 Mac:0014.6A16.C2DA TCP and Server in ver 8

socket:[2] activeLine:(


SCCP ver


mediaActive:0 offhook:0 ringing

0 reset:0 reset_sent:0

paging 0 debug

0 caps:7

IP: 14728 7912 keepalive 1 max_line 2

Note In the Example 5.24 output, ephone-2 (a Cisco IP Communicator) and ephone-3 (a 7912) are auto-registered devices with no ephone configuration in the CME router.

The benefit of having the auto-registration turned on is that you now have ephone entries and MAC addresses for the Cisco IP phones that are trying to register with the CME router. You can then copy and paste the MAC address into a real ephone entry and begin your line configuration for the devices.

Because the auto-registration feature is enabled in CME 4.0 and later by default, there is nothing you need to do to turn it on. If you would like to disable auto-registration, you can access telephony service configuration mode and enter no auto-reg-ephone. IP phones that attempt to register without an explicit ephone configuration will receive a "Registration Rejected" message, as shown in Figure 5.7.

Figure 5.7 IP Phone Message with Auto-Registration Disabled

If you do have auto-registration disabled, you will be able to see the devices that are failing the registration process by entering the show ephone attempted-registrations command, as shown in Example 5.25.

Example 5.25 Verifying Failed Ephone Registrations


Voice# show ephone


Attempting Mac address


Mac Address





13:38:13 ARIZONA Fri







13:38:11 ARIZONA Fri




Telecaster 7960



13:38:25 ARIZONA Fri





Auto-registration is handy because it allows you to see the MAC addresses of the IP phones attempting to register (which you can use for manual configuration). However, it would be much handier if the CME router could assign phone extensions for you...Oh wait; it can! That's the idea behind the auto assign command performed from telephony service configuration mode. This command allows you to specify a range of ephone-dns to distribute to IP phones that register but have no explicit ephone configuration in the CME router.

The auto assign command allows you to distribute specific ephone-dn ranges to specific types of phones or to any phone requesting an extension. For example, you could use the syntax in Example 5.26 to auto-assign ephone-dns 20 through 24 to Cisco 7940 IP Phones, ephone-dns 25 through 30 to Cisco 7960 IP Phones, and ephone-dns 31 through 39 to any other phone model that attempts to register.

Example 5.26 Assigning Ephone-DNs Using the auto assign Command

CME_Voice(config)# telephony-service CME_Voice(config-telephony)# auto assign 20 to 24 type ? WORD 7960, 7940, 7910, 7905, 7906, 7935, 7902, 7911, 7912,

7961, 7961GE, 7941, 7941GE, 7920, 7921, 7970, 7971,

7962, 7942, 7945, 7965, 7975, 7985, anl or bri CME_Voice(config-telephony)#auto assign 20 to 24 type 7940 CME_Voice(config-telephony)#auto assign 25 to 30 type 7960 CME_Voice(config-telephony)#auto assign 31 to 39

As new phones auto-register, the CME router will begin to auto-assign extensions to them. CME distributes the lowest-numbered ephone-dns first and works its way to the high end of the range. If the first IP phone to register was a 7940 model, it would receive ephone-dn 20. If the first IP phone to register was a 7912, it would receive ephone-dn 31. Once the IP phones have auto-registered, the new ephone configuration will appear in the CME router's running configuration. The CME router even adds the optional type command under each ephone to identify the model of IP phone that has auto-registered, as shown in Example 5.27.

Example 5.27 Verifying the Running Configuration After Ephone-DN Auto-


CME_Voice# show running-config

...output truncated... ephone 1 device-security-mode none mac-address 0019.D122.DCF3 type CIPC button 1:21 ephone 2 device-security-mode none mac-address 0014.6A16.C2DA type 7912 button 1:20 ephone 3 device-security-mode none mac-address 0014.1C48.E6D1 type 7960 button 1:22

Note The CME router can auto-detect any supported Cisco IP phone model with the exception of the 7914 Expansion Module. You must manually configure this module under ephone configuration mode.

As soon as you enter the auto-reg-ephone command (which is entered by default) under telephony service configuration mode, IP phones begin to auto-register with the CME router. After they have auto-registered, they will simply sit with a blank line configuration until you restart them. After issuing the auto-assign command, you can then use the restart all command from telephony service configuration mode to get all the lazy auto-registered phones rebooted and assigned new extensions.

Note If you don't plan on using auto ephone-dn assignment to distribute DNs to the IP phones, consider disabling auto-registration for Cisco IP phones in CME, for the following reasons:

■ The show ephone attempted-registrations command gives much cleaner output than the show ephone or show ephone summary command. This makes it much easier to get the MAC addresses of all the IP phones for which you do not have ephone entries. Then, you can manually create the ephones as needed.

■ Even though auto-registered phones don't have an ephone entry in the running configuration, they deduct against the max-ephones value your CME router can support.

■ I steer clear of just about anything with the word "auto" in the Cisco world. My mantra is, "I auto-not use that."

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  • obo
    How to register ephone macaddress?
    9 months ago

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