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New Member

One Way Speech Problem

I have Callmanager 3.1(2)C installed at Main Office and I have PBx at the Branch Office and

this PBX has been connected to Gateway 3640 with FXO port.Everything was workinf fine but

all of sudden without any change to the configuration there erupted the problem of One Way

speech between IP Phone lying at MainOffice and the analog phone connected to PBX at the Branch


Call Manager..RouteHO...Inetrnet...RouteratBranch Office.....Gatewayrouter3640...PBX..analog phone

Kindly suggeste the problem ..

with thanks and regrds

Anil B

New Member

Re: One Way Speech Problem

I have seen many factors contribute to a one-way voice: codec/payload mismatch, wrong RTP ports#, inadequate h245 negociation, but the most common and most probable is a change in ACLs or some new security implementation on the IP routers. RTP ports are assigned dynamically and it is almost impsible to narrow them down to a sizable range in an ACL. This could be verified by the presence of RTP/UDP packets in the ACL logs. Assuming the PBX has nothing to do with this problem and that the Call Manager is taking good care of the signaling, i would suggest questioning some recent IP changes on your network. although you claim otherwise.