SRST. IP phones don't try to register on a SRST device

[MaximBudyonny]

I'm trying to setup SRST in the test environment.

Troubles:

Additional CallManager doesn't appear in a Phone config

when I'm disabling CCM, IP phones don't try to register on a SRST device.

Test environment contains:

1 CCM 4.1(3) IP=10.0.0.12

2 IP Phones 7912 IP=10.100.0.X (default gataway 10.100.0.1)

1 cisco2851 router - SRST device and MGCP gateway IP=10.100.0.1, 172.16.16.1

cisco2851 is registered on a CCM

SRST reference SRST-2 is created onto a CCM. It points to 10.100.1.0

Gateway and IP phones are members of a device pool - default.

The SRST Reference in this device pool is pointed to a SRST-2.

Network routing works properly.

Below is a part of cisco2851 config (some lines was omitted)

DHCP:

ip dhcp pool IP_PHONES

network 10.100.0.0 255.255.255.0

default-router 10.100.0.1

option 150 ip 10.0.0.12

MGCP GW:

voice-port 0/0/0

cptone RU

voice-port 0/0/3

cptone RU

!

ccm-manager fallback-mgcp

ccm-manager mgcp

ccm-manager music-on-hold

ccm-manager config server ccm-test

ccm-manager config

!

mgcp

mgcp call-agent ccm-test 2427 service-type mgcp version 0.1

mgcp dtmf-relay voip codec all mode out-of-band

mgcp rtp unreachable timeout 1000 action notify

mgcp modem passthrough voip mode nse

mgcp package-capability rtp-package

no mgcp package-capability res-package

mgcp package-capability sst-package

no mgcp package-capability fxr-package

mgcp package-capability pre-package

no mgcp timer receive-rtcp

mgcp sdp simple

no mgcp explicit hookstate

mgcp rtp payload cisco-pcm-switch-over-ulaw 126

mgcp rtp payload cisco-pcm-switch-over-alaw 126

mgcp rtp payload-type g726r16 static

!

mgcp profile default

!

dial-peer voice 1 pots

service mgcpapp

port 0/0/1

!

SRST:

call-manager-fallback

max-conferences 8 gain -6

transfer-system full-blind

ip source-address 10.100.0.1 port 2000

max-ephones 30

max-dn 100

system message primary CM Fallback Service

system message secondary CM Fallback Service

keepalive 60

time-zone 26

time-format 24

date-format dd-mm-yy

application

global

service alternate Default

----------------------------------

output of "show call-manager-fallback"

CONFIG [Version=3.4(0)]

========================

Version 3.4(0)

For on-line documentation please see:

http://www.cisco.com/univercd/cc/td/doc/product/access/ip_ph/ip_ks/index.htm

ip source-address 10.100.0.1 port 2000

max-ephones 30

max-dn 100

max-conferences 8 gain -6

dspfarm units 0

dspfarm transcode sessions 0

huntstop

time-format 24

date-format dd-mm-yy

timezone 26 E. Europe Standard/Daylight Time

keepalive 60

timeout interdigit 10

timeout busy 10

timeout ringing 180

caller-id name-only: enable

system message primary CM Fallback Service

system message secondary CM Fallback Service

Limit number of DNs per phone:

Log (table parameters):

max-size: 150

retain-timer: 15

transfer-system full-blind

local directory service: enabled.

output of "show debug"

EPHONE state debugging is enabled

EPHONE registration debugging is enabled

EPHONE ccm-compatibility debugging is enabled

for 30 ephones (too many to list)

But there are no debug messages

[anup.anand]

Could be the typo in the IP address. The SRST IP Address in router is 10.100.0.1, but in the SRST reference it is 10.100.1.0.

SRST reference SRST-2 is created onto a CCM. It points to 10.100.1.0

Please check this in the SRST settings in CCM.

Regards,

Anup.

[MaximBudyonny]

Thank you, but typo is only in my message.

On a CCM IP address of SRST device is correct 10.100.0.1.

May the multihoming (a lot of IP addresses on cisco2851) cause this issue?

On Monday I'll mirror ports on the switch to perform analysis of all traffic between phones, CCM and cisco2851.

As I understand CCM configures IP phones and yet another callmanager (SRST device) must appear in phone's configuration.

When real CCM fails phone starts registration onto a secondary callmanager (SRST device).

As there is only one callmanager exists in a phone's configuration when it fails phone doesn't know what to do.

Phone tries to register on an unexistent CCM in infinite cycle.

May be my CCM is broken? (It doesn't configure phones properly)

[Aaron Harrison]

Hi

The operation of SRST is as follows:

1) When all CMs in the list fails, the phones will try to register with their default gateway.

2) Alternatively, you can set up an 'SRST Refernce' in CallManager (under System/SRST) and then assign this to each IP phone. Then the SRST router will appear in the list of CallManagers in the phone, and the phone will register to this.

Regards

Aaron

Please rate helpful posts...

[sreekumara93]

Hi Aaron,

    If the remote branch gateway and phones are in different DEVICE POOLs what should be happen?

Are the phones can register with SRST gateway?

[Vivek Batra]

Doesn't matter the Device Pool of gateway here. Phone gets SRST gateway reference from its own device pool hence device pool of phones should have correct reference of remote branch gateway to get registered with gateway during WAN fail over.

[sreekumara93]

Thanks Vivek,

One more doubt...

If the remote gateway is a MGCP VG and all the network connectivity  is fine, meanwhile the MGCP protocol down.

Will the phones goes down or continuing by registering with HQ call manager?

Once again thanks for your valuable reply.

[Vivek Batra]

MGCP fallback and phones fallback (SRST) process is completely different, hence irrespective of the MGCP process, if phones fail to register with current CCM Group servers, it will try to register with SRST gateway. MGCP process will run independently.

[k_vishwesh]

hi,

When you say disabling the CCM means are you trying to stop CCM service?.The config looks to be working one.

Can you try to unplug the ethernet cable from CCM and try .

[MaximBudyonny]

I'm disabling CCM in simplest way - just shut down CCM port on a switch. :-)

[mgarciar]

Hi,

I have a similar issue. I have some remote sites with gateways Cisco 2811s and Cisco 1760s with SRST enabled and running H323. If the IP Phones lost connectivity to CCM, only IP Phones 7940s and 7960s are registred in SRST gateway. The IP Phones 7912s and ATAs are not registred. The IP Phones has only one device pool for each site.

I tested with some IOS versions, but it didnt works. I verified with debug ephone keepalive, and the gateway only recieve keepalives from IP Phones 7940s and 7960s. It looks as CCM was the cause of the issue, because IP phones 7912s does not show the SRST gateway as an optional CM on network settings. I do not see any wrong configuration on CCM or SRST gateway. Actually, I am only using very simple configuration on SRST gateway:

------------------------------------------

call-manager-fallback

max-conferences 8 gain -6

ip source-address 192.168.101.1 port 2000

max-ephones 42

max-dn 144

------------------------------------------

The CCM are version 4.2(1).

Someone has an idea?

Thanks in advance,

Marco.

[atroukhatchev]

Hi,

I have the same problem with IP Phones 7912s, SRST on the Cisco2811 router and CM4.2(1).

Did you solve the problem or not?

Andrew.

[johncaston_2]

I've just recently set up a site running CCM4.2 with 7912G phones and 2811 routers and SRST working fine.

Have you added the Device Pool to the phone and have you added an SRST reference to that Device Pool? A phone won't automatically register with the router unless it's configured to do so on the CCM - the documentation's not very clear on that. It takes a couple of minutes for it to fallback to SRST mode or you can just reboot the phone to hurry it along.

Let me know how you get on. If you don't have any luck I'll have a closer look at your config or paste mine in.

Cheers,

John

[Jericho1979]

Hi John.

May I answer on last message.

Yes, we have Device Pool with SRST reference to 2811 router. All 7912 contain this Device Pool.

[mgarciar]

Hi,

my issue was solved. I had configured CM?s name on Cisco CM setting; I didn?t have DNS on the network. I changed CM?s name for IP Address, and it started to work fine (I don?t remember if was neccesary to reset the IP Phones after change the setting).

Try using IP Address on CM setting.

Regards,

Marco.