a network node is configured to negotiate for connections for high priority calls received at the node in the face of otherwise congested outbound communication links . the negotiation is conducted in a fashion that will preserve connections for existing calls associated with the node . for example , the negotiation may be conducted so as to cause one or more of the existing calls to consume less bandwidth over the outbound communication links than was consumed at a time prior to reception of the high priority calls . such negotiations may be initiated depending on the availability of codec resources and / or compression schemes at the node and may be conducted using oam cells .