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I have fedup from keep troubleshooting the SRST, some of my phones are getting registered and some are not getting registered to SRST router ...

i am surprised why one phone has registered why other not!!! both the phones have same model both are getting the same subnet ip .... the phone which is not getting register it is giving me error " Registration Rejected:Max Pho... " i dont why some of phones are not getting register.

about CCM config i created one SRST, called tht SRST in Default Device Pool and assign Default DP to the phones ...

can any one tell me why this msg is coming on phones ...


Hall of Fame Super Red

Re: SRST Prob

Hi Riaz,

This error;

Registration Rejected:Max Phones

indicates that the number of IP phones that are trying to register with the SRST Router has exceeded the number supported by the SRST Router. The number of supported phones is based on the SRST Router Model;

Here are the number of supported phones per SRST Router;

Cisco 880 SRST Series Integrated Services Router

Up to 4 phones

Cisco 1861 Integrated Services Router

Up to 8 phones

Cisco 2801 Integrated Services Router

Up to 25 phones

Cisco 2811 Integrated Services Router

Up to 35 phones

Cisco 2821 Integrated Services Router

Up to 50 phones

Cisco 2851 Integrated Services Router

Up to 100 phones

Cisco 3825 Integrated Services Router

Up to 350 phones

Cisco Catalyst® 6500 Series Communications Media Module (CMM)

Up to 480 phones

Cisco 3845 Integrated Services Router

Up to 730 phones

From this good SRST doc;

Hope this helps!


New Member

Re: SRST Prob

hi Rob,

Thanks for your reply, in start i also thought that this msg is bcoz of number of max phone registered .. but if i do "sh call-manager-fallback all" command, in it it shows me only 29 phones are registered ...

one thing i would like to mention that i have 2821 Router having SRST 4.0 and i have 7911 & 7942 phones in network, 7942 phones are not supportable in SRST 4.0 (when 7942 goes on SRST Router it only displays that "CCM Fall back Service Operating" msg on screen and rest of all screen is empty ) do you think that even the 7942 phone is not completly registered with SRST Router, Router will count it as ephone ????

Please reply urgently,


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