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Pushing for IP telephony...Help needed


I am trying to convince our management to deploy VoIP and reduce heir spending for Legacy PBX systems. I was able to get their approval to install Cisco ip telephony products in a limited area & limited budget, probably to test the solution.

I need help with design and product selection in order to make this a success.

The area (building/company) where I am planning to deploy IP telephony was recently acquired by our company. It is located 300m away from us so probably we will be connecting it to our LAN(either fiber or wireless). The building has a meium sized PBX (approx. 200 extensions). After the acquisiton there were plans to have a tie line between our PBX and the acquired one, but those plans were scratched since the latter broke down (and I got my chance). Since not many employees remain in the acquired building, the number of extensions required is around 30.

I got a suggestion from a Cisco Partner and would like to know your comments:

- VG248 Analogue Gateway

- 2821 with CCME (48 phones), 2 x 4port VIC FXO (universal), 2 x channel packet voice/fax dsp module, 1 x Ip communications high density digital Voice NM with 1 T1/E1

The idea is to use the existing telephones in order to keep cost minimum.

- I would like to know that if we have 6 direct lines (PSTN) that will terminate on the FXO, there would be no need for an E1 line hence no need for the 2821 E1 card, right?

- Will the caller ID function on the existing phones using this design?

- Any comments on the solution provided?




Re: Pushing for IP telephony...Help needed

CCME does not support VG248. Check this link under Restrictions for Analog phones.

An alternate would be to use a VG224 (for 24 ports) and a EVM on the 2821.

The EVM base board supports 8 FXS and you can add a 6 port FXO module. That should meet your requirements.

To answer your questions

1. Yes, you are right. Since your PSTN lines are all FXO's, you don't need the E1 card.

2. Caller ID is supported in VG224 as well as EVM



New Member

Re: Pushing for IP telephony...Help needed

Thanks Anup for your reply...

I quickly checked the EVM specs and found that only 1 is supported on 2821. This means that there is no room for future expansion if more extensions are required. I am thinking of getting VG248 and CCM MCS hardware (probably 100 uer license). And probably I can add an EVM to the 2821 if more ext. are required.

Please tell me if there are any other ideas that support future expansion.



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