2 Office VOIP design, and PVDM usage

Question

Dear colleagues,
i have 2 , A and B sites, with same spec's "number of users 16 with IP phones, and just VOIP needed , both will connected via Internet using a FW then IPsec to other branches",
for VOIP solution
A:will call PSTN via 4 analog lines, so i need 4 FXO
B:will call PSTN via VOIP provider so no FXO needed
each branch will call other branches using VOIP h323 trunks
my questions are,
1- PVDM needed?? for both sites?? why PVDM needed??
2-and if both sites will not call PSTN, directly, i.e if i used send landlines calls from the branch to my central office, i.e if i didnt use analog line nor VOIP provider to contact PSTN, IS PVDM NEEDED IN THIS CASE??
your help is appreciated
thanks

Answer 1

Hello Ahmed,
Hope I'm answering all your questions
A-hereunder example of VOIP senario and give me your commect.
1-if phone 1 call phone2, no transcoding needed?
No. Calls between phones controlled under the same CME will use G.711 and both phones supports G.711.
2-if phone 1 call phone 3, transcoding needed?, if needed, what CME is responsible for transcoding?, how it done, from both drection of voice traffic?
No. Call will be in G.729 and will work since Cisco IP phones (besides G.711 and other codecs) supports G.729. If for some reason phone 3 doesn't support G.729, then CME_b needs a transcoding resource to connect the call successfully.
B-Unity Express used only for Voice mail?, or it has another functions?
Supports Voicemail, Integrated Messaging, Auto Attendant, IVR and Fax.
C-if there is a CME router without PVDM module exist, can this router contain unity express?
Yes.
D-when i access unity express from CME CLI, i can use below command:
Yes. That command is used to access CUE via CLI, although you can use GUI as well.
E-what is this service-engine 0/0?, is it the AIM module??
Yes.
F-from the same CME router
1-there is PVDM2-32, and PVDM2-16, how i can choose the PVDM needed for my network?
Depending on the requirements (i.e. connections to PSTN, conferencing, transcoding, etc) you will need to calculate the total number of PVDMs. For this you can use the Cisco DSP Calculator: http://www.cisco.com/web/applicat/dsprecal/dsp_calc.html
2-the AIM service engine 0, is it the Unity Express??
Yes.
3-when i access it , i use service engine 0/0, why 0/0, it is AIM 0 only, there is no 0/0?
The AIM is installed in slot 0, subslot 0.
F-what is related configuration to PVDM?, i.e, is there any provisioning configuration commands?
The most common is for conferencing and transcoding resources. Check this: http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/interop/intcnf2.html
G-when transcoding done by PVDM, it it need any configuration or done automatically?, i.e if G711 tranlated in real time to G729, is it use a specific commands in the run config, or just the existance of PVDM make the transcoding done automatically?
You configure the resources as shown in the link above. Once you get the resources registered and configured correctly, they will be invoked by CM/CME automatically when the situation demands.
H-is there is any config needed to provision AIM?, or just access the service engine and config the voice mail?
You first configure IP connectivity to the module. Check this: http://www.cisco.com/en/US/docs/voice_ip_comm/unity_exp/design/design21/cuenwinf.html#wp1008330
Next you can access it via CLI or GUI for configuration and integration to CM/CME.
http://www.cisco.com/en/US/products/sw/voicesw/ps5520/products_configuration_example09186a008037f2a9.shtml#t11
http://www.cisco.com/en/US/products/sw/voicesw/ps5520/products_configuration_example09186a0080289ef0.shtml
Hope it helps. Thank you for the ratings.
-- Adrian.