Hears ringing of incoming call during current call - help

I have invested 40+ hours trying to solve this issue, and I’m edging toward insanity.

Steps taken sofar

Polycom firmware:


standard extension macro


  1. A caller is on the phone
  2. A new call comes in
  3. Caller hears annoying ringing

Is there anything that can be done?


This is really a Polycom question.

You can, however, set call limits, but there are some subtleties and I’m not sure of them all. These may stop you doing thing that you still want to do.

From what I can remember, our Polycoms just flash a light when there is a second call incoming.

Hello all,

this was already discussed => here <= and UCS 3.3.2, SIP 3.2.6, SIP 3.1.8 should have addressed this issue if it matches the one reported under VOIP-68267.

Checking your log file for an entry, when the issue happens , like:

net 4 00 rtosNetwork: netwTask() - Can’t find associated CCB!
so 4 00 soTonePlay: Could not find a free DspSe channel.

You can force the Phone to upload it’s current App and Boot Log via a Finger Combination documented in the Admin Guide for your SIP / UCS Version.

This issue usually only happened after a Blind Transfer was executed.

Reproduction Step:

  1. Phone A calls phone phone B.
  2. Answer on phone B with the handset, press transfer and dial phone C.
  3. while phone C is ringing, replace the handset on B to complete the transfer.
  4. Answer the call on phone C and terminate the call.
  5. Place a new call from phone A to Phone B.
  6. Answer on phone B by lifting the handset.

Expected Result: Ringing dialtone Should not be heard during the conversation.

possible observed Result: While in Conversation heard Ringing dialtone.

If above appears and you can see the suggested Log Levels please liaise with your local Polycom Reseller and and escalate the case to Polycom Support.

Best Regards

Steffen Baier

Polycom Global Services