IP Phones Not Registering During call-manager-fallback/SRST Mode

Matthew Martin · ‎06-24-2016

Hello All,

Gateway: ISR4321/K9
IOS-XE Version: 03.13.04.S
IOS Version: 15.4(3)S4

I am trying to test the SRST failover of an ISR Router, but after I cut the connection to CUCM, the IP Phones never actually register to the Router. See below for configuration...

CALL-MANAGER-FALLBACK:

call-manager-fallback
secondary-dialtone 9
max-conferences 2 gain -6
transfer-system full-consult
timeouts interdigit 5
protocol mode ipv4
ip source-address 10.18.2.1 port 2000 !--> 10.18.2.1 is the Voice Vlan IP Address on ISR4321
max-ephones 12
max-dn 48
default-destination 4019

I also configured a TEST-DP and a TEST SRST Reference on CallManager (*v8.6) and applied that Device Pool to the H.323 Gateway I added to CallManager for this ISR Router. Is there anything I am missing that also needs to be configured to have the Phones Register to the Gateway? I tried running "debug ephone register/state" but no information is printed to the logs when the connection to the CallManager is lost.

SRST Reference Configured on CUCM:

TEST-SRST
Name: TEST-SRST
Port: 2000
IP Address: 10.18.2.1

This SRST Reference was then applied to the Device Pool I created which is what I set the H.323 Gateway's Device Pool too.

But, for some reason it doesn't seem like SRST is working at all. We have the FL-SRST and FL-CME-SRST-5 Licenses.

If anyone has any thoughts or suggestion, it would be very much appreciated.

Thanks in Advance,
Matt

Suresh Hudda · ‎06-24-2016

Have you applied that DP to those phones as well ? Are you able to see srst IP address in phones, when they are registered to cucm ?

Suresh

Matthew Martin · ‎06-24-2016

Hey Suresh, thank you for the reply, much appreciated!

Sorry, I actually realized I didn't mention that after I submitted the question... But, yes the TEST-DP was/is applied to the 2 IP Phones I'm testing with (*2 x 7941s).

As for seeing the SRST IP Address in the Phones... Where should I be able to see that in the phone, would that be the Default Gateway (*currently set as 10.18.2.1)..? If so, I think that might be the problem.

I forgot to mention this in the OP... Since the ISR4321 doesn't have PoE ports for phones, we also have a 2960X switch connected to the ISR Router. The 2960X switch has the DHCP Pools and Vlans configured on them, so I was incorrect in stating that 10.18.2.1 was the Voice Vlan IP Address. 10.18.2.1 is actually the Sub-Interface address on the ISR connection to the switch.

ISR4321 Gi Interface Configuration:

		!
		interface GigabitEthernet0/0/1
		 description Uplink to Switch
		 no ip address
		 negotiation auto
		!
		interface GigabitEthernet0/0/1.1
		 description Inside 10.18.1.1 Interface
		 encapsulation dot1Q 1 native
		 ip address 10.18.1.1 255.255.255.0
		!
		interface GigabitEthernet0/0/1.2
		 description Inside 10.18.2.1 Interface
		 encapsulation dot1Q 2
		 ip address 10.18.2.1 255.255.255.0
		 h323-gateway voip interface
		 h323-gateway voip bind srcaddr 10.18.2.1
		!

Then on the 2960-X I have the Vlans and DHCP Pools configured like this below:

2960-X Vlan Configuration:

		!
		ip dhcp pool PCs
		 network 10.18.1.0 255.255.255.0
		 default-router 10.18.1.2 
		 dns-server 192.168.5.35 10.50.1.3 
		 domain-name jwpepper.com
		!
		ip dhcp pool PHONES
		 network 10.18.2.0 255.255.255.0
		 default-router 10.18.2.2 
		 option 150 ip 192.168.11.8 192.168.11.9 10.50.2.9 
		 dns-server 192.168.5.35 10.50.1.3 
		!...
		!.........
		!...
		interface Vlan1
		 description PCs and printers
		 ip address 10.18.1.2 255.255.255.0
		!
		interface Vlan2
		 description Voice VLAN
		 ip address 10.18.2.2 255.255.255.0
		!
		ip default-gateway 10.18.1.1

Is the configuration above what is causing my problem?

Sorry, the original configuration of the remote sites, which is where these devices will be going, only had a single C1861 Router/Switch so the configuration of that was much easier... SO I must just be mixing something up here...

Thanks Again,
Matt

Suresh Hudda · ‎06-24-2016

You can check srst reference on IP phone under Device Configuration Menu then go to unified communication options..there you see primary, secondary, tertiary (if any) and then srst IP address as well.

As far as VLAN/network configuration concerned, I'm not sure as I'm not expert on that, but if IP phone is reachable from gateway then they should register.

Pls attach sh run as well of h323 gateway...will check in morning..hope someone can look on that as well now.

Suresh

Matthew Martin · ‎06-24-2016

Sure I will post the config...

Also, does the IP Address of the SRST Reference in CUCM, the Gi0/0/0.2 interface's h323-gateway voip bind srcaddr, and the Voice Vlan's IP Address, do they all need to match?

*The Config of the H.323 Gateway, which is the ISR4321, is attached.

-Matt

Deepak Mehta · ‎06-24-2016

Hi Matt,

Defualt router for SRST phones should be the same as defined in CUCM -10.18.2.1.This router should be the Cisco Unified SRST router because this is the default address that is used to obtain SRST service in the event of a WAN outage.

Matthew Martin · ‎06-24-2016

Hey Deepak,

Ok, so I do have the IP Source Addresses correct then. Not sure what the problem is then.

-Matt

Deepak Mehta · ‎06-24-2016

Hey Matt,

I think inside the dhcp config the defualt router should be same the router used for srst which is 10.18.2.1 not 10.18.2.2....this is what i meant to say earlier.

Matthew Martin · ‎06-24-2016

Ok, so I modified the configuration to the following:

Phones DHCP Pool on 2960 Switch:

ip dhcp pool PHONES
network 10.18.2.0 255.255.255.0
default-router 10.18.2.1
option 150 ip 192.168.11.8 192.168.11.9 10.50.2.9 10.18.2.1
dns-server 192.168.5.35 10.50.1.3
!

So I added/modified the bolded text in the dhcp pool above. And then I rebooted the phones, waited until they came back up and registered with the CUCM. After they were registered I cut the connection between the Router and CUCM and the phones just continuously say registering... It's been about 10 mins now since I cut the connection, but the phones still haven't registered to the Router...

What about on the Router/ISR Device? Should I have add anything on there? Do I need to define the the 10.18.2.1 address in:

sccp ccm 10.18.2.1 identifier... version...

and then add it to

sccp ccm group 1

Not really sure what else I can try... Anymore ideas?

Thanks Again for the replies, very much appreciated!

-Matt

Deepak Mehta · ‎06-24-2016

Hi Matt,

Phones only support two IP addresses for Option 150 values as TFTP Server 1 and TFTP Server 2 entries so you may want to the router ip to TFTP 2.

Matthew Martin · ‎06-24-2016

Ok I modified the DHCP Pool again to this below:

ip dhcp pool PHONES
 network 10.18.2.0 255.255.255.0
 default-router 10.18.2.1 
 option 150 ip 192.168.11.8 10.18.2.1 192.168.11.9 10.50.2.9 
 dns-server 192.168.5.35 10.50.1.3

I moved the Router IP Address to position number 2 on option 150 line... Then I powered off the IP Phones and plugged them back in. I then let them Register to the CallManager and waited about 5+ minutes after they were registered, then I killed the connection to CUCM. And that was about 5-10 mins ago now and they still say Registering...

If I go to here on the ip phone I can see that 10.18.2.1 is configured as the TFTP Server 2...

Any other ideas?

Thanks Again,
Matt

Deepak Mehta · ‎06-24-2016

Hi

Apart from what suresh suggested can you confirm ,what is the model of the phones?

do you see phones getting unregistered once you break the connectivity to CUCM?

Matthew Martin · ‎06-24-2016

Deepak, thanks for the reply.

They are CP-7941Gs... And yes, once I cut the connection to the CallManager I can see in CUCM > Devices > Phones, that the 2 test phone's status now says "Unregistered".

Thanks Again,

Matt

Matthew Martin · ‎06-27-2016

Deepak/Suresh,

I was watching the video at the link below on configuring Basic SRST on Cisco Routers. After the person in the video configures the SRST Reference in CUCM and then adds that SRST Reference to the Device Pool the CIPC is registered to, his IP Communicator now shows the IP Address of the SRST Reference he added to the Device Pool and "Unified CM" #2...

https://www.youtube.com/watch?v=H2ogaWYq5QA

However, when I do the same thing for the Device Pool that my test phones and Router are Registered to, I never see the SRST Router's address listed in the a Unified CM Configuration page/list on the phone... Should I be seeing the SRST Reference's IP Address listed on the phone somewhere?

Thanks Again,
Matt

Suresh Hudda · ‎06-27-2016

Hi Matt,

No, you don't need to mention srst router IP address in cucm apart from SRST reference. Try to create another one dummy (srst reference, device pool and new phone) and check.

Is dbreplication is fine in cucm ?

Suresh