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New Member

VoIP Packet trace

Hello ,

I have one  strange issue but need to justify my boss why it is like that.


  • Location A and Location B, when location B call location A from a 8945 phone to a TP SX20 the video is seen by each other but when the location B call from TP SX20 to location A SX20  the video is not seen,   the IP phone and the TP SX 20 are in the same subnet on location B,How i shld i justify the problem is lying where??? I need to trace the incoming and outgong traffic from TP and from the IP phone,how can i do that???
  • If my cucm publisher 9.1  is DHCP server for ip phones if i shut down the publisher DHCP will work with cucm subscriber 9.1, Is it DHCP redundancy is available in 9.1 since it was not available in 6.1



  • IP Telephony
VIP Super Bronze

1. You need to look at cucm

1. You need to look at cucm traces to see why video is not working...enable detail cucm traces, download the logs via RTMT...


2. DHCP should continue to work as log as you have enabled DHCP service on both servers. When the phones send a dhcp request one of the servers should respond..However you shouldnt be using cucm for DHCP...Thats not good.

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"
New Member

Dear,Well i will do the trace


Well i will do the trace i will reply accordingly.

For DHCP if suppose on my core 6500 below are the configs, according to the below configs if a ip phone request for ip it will go to both helper address, so in our case you mean to say that any server will reply, so you mean to say that for DHCP both server are active and in sync for their scopes and whatever their assignments of IP addresses.

int vlan 2

ip address

ip helper-address ---CUCM Publisher

ip helper-address ---CUCM subscriber


New Member

DearsAnybody can help me for


Anybody can help me for the dout of the DHCP.

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