Sorry Guys, My Google Fu is failing me on this one. I know something like this exists and maybe one of you has it squirreled away or knows where to find it.
TLDR at the bottom.
I have a customer that currently has 4 active QSIG Trunks between a SX-2K and Cisco Call Manager across 2 locations. They also have a total of 8 PRI Trunks (4 at each location). All of this is going to be transitioned over to the Cisco. The 8 PRI's will be transitioned to SIP early on and the Mitel Handsets (about 3000) will be moved over a timeframe of about 18 months.
Initially, when the SIP trunks are installed, the traffic to the Mitel over the QSIG trunks will increase significantly and will fall off gradually as the Mitel handsets are transitioned.
There are 2 areas in this where traffic capacity is a concern to the customer.
[ol 1]
[li]How Many SIP Trunks will be required to replace the existing PRI's for both sites[/li]
[ul]
[li]How Many QSIG Channels will be be required. This one is of the most concern[/li]
[ul]
[/ol]
TLDR:
I know, or at least I am very confident, that I've seen a graph that represents the the number of channels needed in a given PRI based on estimated traffic. I am also sure that the graph is not linear. As such, adding a 5th Qsig trunk does not only add an extra 25% capacity, but actually significantly more than 25%. I'm guessing around 50%. If I need to document this, guess work will not be sufficient, thus I need that graph. Does anyone have one handy or know where I can find one?
TLDR at the bottom.
I have a customer that currently has 4 active QSIG Trunks between a SX-2K and Cisco Call Manager across 2 locations. They also have a total of 8 PRI Trunks (4 at each location). All of this is going to be transitioned over to the Cisco. The 8 PRI's will be transitioned to SIP early on and the Mitel Handsets (about 3000) will be moved over a timeframe of about 18 months.
Initially, when the SIP trunks are installed, the traffic to the Mitel over the QSIG trunks will increase significantly and will fall off gradually as the Mitel handsets are transitioned.
There are 2 areas in this where traffic capacity is a concern to the customer.
[ol 1]
[li]How Many SIP Trunks will be required to replace the existing PRI's for both sites[/li]
[ul]
[li]Site 1 currently has a max simultaneous usage lower than 40 channels[/li]
[li]Site 2 Currently has a max simultaneous usage lower than 30 channels[/li]
[li]My thinking on the SIP is to design it for 70 channels with extra capacity via bursting[/li]
[/ul][li]How Many QSIG Channels will be be required. This one is of the most concern[/li]
[ul]
[li]If it is a one to one relationship we will need approx 70 more QSIG channels initially[/li]
[li]Currently we are using about 23 of 96 channels and adding 70 will be 93 of 92[/li]
[li]We have a 5th QSIG trunk tested and waiting to add capacity up to 115 making it 93 of 115[/li]
[li]This is where the customer wants a written proposal outlining how the capacity will be sufficient[/li]
[/ul][/ol]
TLDR:
I know, or at least I am very confident, that I've seen a graph that represents the the number of channels needed in a given PRI based on estimated traffic. I am also sure that the graph is not linear. As such, adding a 5th Qsig trunk does not only add an extra 25% capacity, but actually significantly more than 25%. I'm guessing around 50%. If I need to document this, guess work will not be sufficient, thus I need that graph. Does anyone have one handy or know where I can find one?