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Stupid issue cannot hear anything

Stupid issue cannot hear anything

Hi All,

I'm using 3com phone solution and i have two branches . I used to use 3com switch 5500 as a DHCP server and at one day this switch failed down in one branch so now i'm using windows 2003 server to play the DHCP role , with he option 184 .

My problem now is i cannot do calls to the other 3com phone system in the other branch .

When i place a call , the other party recieve it but does't hear anything .

Please advice.


RE: Stupid issue cannot hear anything

You use sip or vtl ?? have you create pool for ip-on-fly?

RE: Stupid issue cannot hear anything

Hi ,

i'm using SIP and the interface is NBX call processor.

i don't know what do you mean by the ip on fly ?



RE: Stupid issue cannot hear anything

Hi , ok ip-on-fly is used only for VTL , sip not use ip-on-fly . Than

1. each device had correct gateway ? Normally NBX Phone for Local voice not used IP but use L2 , than you verify if each phone has default gateway configured
2. in your router disable SIP-ALG or SIP-INSPECT

RE: Stupid issue cannot hear anything


the only modofication done is my DHCP role which is assigne to widnows server 2003 , i have only one question please :

the DNS , should i configure it with any thing ?


M Farag

RE: Stupid issue cannot hear anything

No DNS for NBX is not important for voice .

RE: Stupid issue cannot hear anything

o.k , i'll tell you some notices and hope that can help you understand my problem.

when i call the other party , i hear nothing but the other party recvieve a ring phone but when he answer we don't hear each other .

also when the other party call me , i recieve nothing at all even no ring phone.

i'm linking the two nraches using MPLS , do you think this MPLS have a problem ?


M Farag

RE: Stupid issue cannot hear anything

Sorry , you have two NBX one on branch1 one onbranch2 ? or you have one NBX on Hq and one-more phone on branch2?

RE: Stupid issue cannot hear anything

this will never work using the 2003 server as the dhcp server the 3com phones need to gateway through a hardware based gateway ,the problem points to the dhcp change made

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