What Determines maximum allowed dn in srst

[syruspayne]

Cisco 2951 router can support up to 250 ephones and 500 dns in srst as per the chart here:

https://supportforums.cisco.com/discussion/11670501/error-exceed-limit-while-adding-ephone-cme-2921

However, I am only able to configure 20 dns even though I see that I should be able to configure 500 after doing " max-dn ? "

I will like to know what actually determines the number of dn's that can be configured on the router

will it be memory, dsp, license etc?

Thanks

[Shashank Mahajan]

It depends on the DRAM installed on your Cisco 2951 router. The following link shows Cisco 2951 can support upto 250 IP Phones and 500 Ephone-dns or Virtual Ports provided you have got 1GB of DRAM installed on it.

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cusrst/requirements/guide/srs11spc.html

It also states that "Memory recommendations and maximum numbers of IP phones are for common Cisco SRST configurations only. Systems with large numbers of phones and complex configurations may not work on all platforms and can require additional memory or a higher performance platform."