Minimum Bandwidth required for an IP phone(BO) to register with CCM(HO)

Answered Question
Apr 6th, 2010


Hope you all doing well...would need clarification from the design perspective...

Let's say i am deploying a multisite WAN with Centralized call processing network. I am installing an IP Phone at a branch office with 64kpbs pipeline. what is the minimum bandwidth required for this IP Phone to collect the config files from the tftp and register with the ccm (at HO)?
Is there any min bandwidth guaranteed for this?



Correct Answer by Jaime Valencia about 6 years 10 months ago

The topic is fully covered in the SRND

Bandwidth Provisioning

There are tables that already provide the math for X amount of numbers.



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Paolo Bevilacqua Tue, 04/06/2010 - 04:11

The BW to register is not much, but you also have to consider how many phones may try to register at the same time.

karthiksr Tue, 04/06/2010 - 04:39

Thanks for your response.

Assuming only one IP phone at BO.

Just wanted to know if there is any real data suggesting the exact bandwidth number that may required for the phone, which will be helpful for me to be specific for documentation.



Paolo Bevilacqua Tue, 04/06/2010 - 05:40

Are you new to VoIP?

Since you need about 30 Kbps for using the phone anyway, there is no point worring about registration.

karthiksr Tue, 04/06/2010 - 23:00

Knew codec's and their usages.

But in an actual deploying environement haven't encountered (if there is any thing like guaranteed bandwidth; not much of as said by bevilacqua; but may be consumed by an ip phone to make its fresh registration), as very well we knew that the bandwidth 64k is enough to establish call using G729 WAN end. More over the 64k pipeline is used for voice and data.

Thanks for sharing the link. Went through the topic. It's useful.


noc mcc Wed, 04/22/2015 - 00:33

this gives 404 page not found error..Please share this document.I want to know specifically about the bandwidth required by 9971 phone during registration


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