C3925-CME-SRST/K9

[ciscoguy88]

Hi Guys,

Can I check can I use C3925-CME-SRST/K9 model to support 700 users for the voice?

As currently we only support 200 users and we are moving into new building or should we replace it with a new model?

[Nithin Eluvathingal]

Please refer below link.

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucme/requirements/guide/cme12spc.html

[ciscoguy88]

Thanks a lot for the link. 

It seems 3925 model can only support 250 IP phone.

So if got 700 users, how should we go about it as I don't see a model which can support such amount of IP phones.

Thanks in advance.

[Nithin Eluvathingal]

Go with a BE6K. More informations on below link.

https://www.cisco.com/c/en/us/products/unified-communications/business-edition-6000/index.html

[ciscoguy88]

BEK6 is a whole new solution?

Actually I have existing cisco call manager in my data center.
So just want to know on the voice gateway model in my office if it can support more than 700 users.

So currently no other cisco ISR model which can support such amount? We need to change the whole phone architecture?

[Roger Kallberg]

By the information provided I assume you are using CME. If so a 4431 should be what you need. It can if I remember correctly handle 1000 devices.

[ciscoguy88]

I check 4431 can support up total 350 IP phones only.

We have existing Call Manager in our data center. So currently is the voice gateway router that I'm checking if we need to replace it if we move into new building and if our existing model 3925 can support more than 700 IP phones.

But from above link it seems cannot. Does it mean, we need to replace our phone architecture or actually the specs in cisco website is only estimation?

[Nithin Eluvathingal]

correct me if I am wrong. asper your last reply,  you are using CUCM in Data center and 3925 is used as voice gateway.  you are moving this  voice gateway to new location. 

• what's your current setup
• are you using CME or CUCM
• what's the current role  of 3925
• how many locations you have 

[ciscoguy88]

Hi,

Sorry I'm newbie in this Cisco phone system.

Actually we are not using CME. We are using CUCM.

So basically 3925 is just the voice gateway for our current office phone system routing to the CUCM.

So if it is just a gateway, actually the one who determine the amount of IP phone can be use is the CUCM system in our data center, correct?

So voice gateway 3925 just route traffic and nothing to do with the amount IP phone it can support, right?

So if we move to new office, we still can use existing 3925 as the voice gateway right even though our user increase to 700 people instead of current of 200.

[Nithin Eluvathingal · Accepted solution]

So if it is just a gateway, actually the one who determine the amount of IP phone can be use is the CUCM system in our data center, correct?  YES

So voice gateway 3925 just route traffic and nothing to do with the amount IP phone it can support, right? no. it can also be used for SRST. in that case the number of phones registering during the SRST depend on the router capacity.  I am not sure if the gateway is acting as both gateway and SRST router.

So if we move to new office, we still can use existing 3925 as the voice gateway right even though our user increase to 700 people instead of current of 200. if you are using the 3925  as a voice gateway and not using SRST feature, to cover the additional users  you just need to add required  license in CUCM . if you plan to use the router  for both VG and SRST, you need consider the router capacity  and SRST license on gateway. 

[Jaime Valencia]

I strongly suggest you reach out to a reputable consultant or a Cisco partner WITH voice specializations to further discuss this.

If you're increasing the amount of users/devices, does the OVA support that?

Do you need to add redundancy on CUCM? Would you need CoW?

Have you accounted for the necessary BW required for the new devices?

Have you taken into consideration if more media resources are needed?

Does the GW has enough capacity for the amount of PSTN calls you would need with 700 users?

Do you need SRST, and if so, for how many users?

[ciscoguy88]

Thanks a lot all. Appreciate it.

I think looking for the consultant in this voice would be better as I'm newbie in this current setup.

[Roger Kallberg]

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@ciscoguy88 wrote:
I check 4431 can support up total 350 IP phones only.

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Your right, I had it mixed up with number of devices supported for SRST. For a 4431 that would actually be 1200.