To factor 203 trunks(T1/E1) on the voice gateway

[Sumit Bhargava]

Please advice how can I factor 203 trunks(T1/E1)  on multiple voice gateway and which device should be used.

(on Cisco 3945 ISR max 8 T1/E1 can be factored)

Regards

Sumit

[William Bell]

Sumit,

Actually, eight is the maximum capacity for on-board T1/E1 ports but you can extend capacity by installing Network Modules.  Achieving a total of 24 T1/E1 connections.  By trunks are you referring DS-1 or DS-0?   I ask because some folks look at each B-channel in an ISDN bundle as an individual trunk.  Anyway, take a look at the following table to get a high level overview of platform positioning within the Cisco ISR family.

More detail on physical port limitations are provided in the following figure:

One key point to keep in mind is that the 28xx/38xx ISR does not perform to the same level as the generation 2 (29xx/39xx) ISRs.  For example, notice that the 3845 can terminate the same number of T1/E1 ports as a 3945 but the 3845 can only handle 450 concurrent voice calls tops (yes, you can over provision and create a blocking situation).

Now if you are looking for 203 T1/E1 circuits then you may want to consider T3 circuits and look at the AS5350 or AS5400.  I haven't used these products in a very long time as they are positioned for contact center and service provider arenas. 

HTH.

Regards,
Bill

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[Sumit Bhargava]

Hi William!

Thanks for your prompt reply.

Here, trunk refers to DS-1

Regards

Sumit

[William Bell · Accepted solution]

Gotcha. Well, then you are in a service provider scenario and you may want

to look at the gateways (like the as53xx and as54xx) that operate in that

market. There may be others that I am not familiar with. Of course, if you

have the need to geographically disperse the gateways than the 39xx ISR may

work for you. Other factors come into play which need to be considered

before making a gateway choice.

HTH.

Regards,

Bill

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On 7/3/10 11:45 AM, "sumitbhargava"

[Sethuramalingam Balasubramanian]

Thanks Bill for the reply. I am interested to know how this E1/T1 capacity would change when we use the same ISR G/W's for both inbound and outbound, considering the fact CPA will be required for outbound calls. Can we have the same chart with combination in place?

Also, is there a document where partners can refer to this for capacity sizing for both inbound and outbound?

Thanks!

-Sethu