Отключаем функционал сигнала flash на Linksys/Cisco SPAxxx

Через provisioning:

  <!-- Supplementary Service Subscription -->

  <Call_Waiting_Serv_2_ ua="na">No</Call_Waiting_Serv_2_>

  <Three_Way_Call_Serv_2_ ua="na">No</Three_Way_Call_Serv_2_>

  <Three_Way_Conf_Serv_2_ ua="na">No</Three_Way_Conf_Serv_2_>

Или аналогично вручную.

Для надежности можно call-limit=1 в sip.conf.

Signaling Hook Flash Event

The Linksys ATA can signal hook flash events to the remote party on a connected call. This feature can be used to provide advanced mid-call services with third-party-call-control. Depending on the features that the service provider offers using third-party-call-control, the following three Linksys ATA features may be disabled to correctly signal a hook-flash event to the softswitch: • Call Waiting Serv • Three Way Call Serv • Three Way Conf Serv You can configure the length of time allowed for detection of a hook flash using the Hook Flash Timer parameter on the Regional tab of the administration web server.