[asterisk-users] estimation on phone network capacity

[Alex Balashov]

mark morreny wrote:
> Hi
> 
> I am working on deploying voip for my company and would like to seek 
> some advice on the number of E1 lines we need to rent.  Our telco told 
> us that there can be at most 30 concurrent channels on an E1 line.  
> Typically, what is the maximum number of DIDs that we can allocate to 
> that E1 line before users get frequent "all lines are busy"?  We are 
> running a support center with mostly incoming calls.  Is there any rule 
> of thumb that are typically used for this kind of estimation?

That depends on the application.

In general, phone lines for voice (not fax or modem) are considered to 
have a 30:1 oversubscription ratio, but that can vary immensely.

Also, it is instructive to inquire what portion of the DIDs will be used 
with what frequency, and whether the distribution is truly uniform. 
VoIP is a DID-intensive industry;  often, DIDs are assigned to every 
employee in an organisation so that everyone has one in principle, even 
if relatively few people actually use them.

-- 
Alex Balashov
Evariste Systems
Web    : http://www.evaristesys.com/
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