Patent ID: 8223748
Filing Date: 2012-07-17
Classification: H04L

Abstract:
1. A method for refreshing a session, the method comprising: determining, by a first device, during a Session Initiation Protocol (SIP) session between the first device and a second device, whether a refresh method is supported by the second device by sending a negotiation message to the second device indicating that the refresh method is supported, wherein a device that supports the refresh method is configured to determine whether a SIP session is active or inactive, and wherein the first device is configured to send a message with a body when the refresh method is not supported; receiving, at the first device, a response from the second device indicating whether the second device supports the refresh method; based on the response from the second device indicating that the second device supports the refresh method, generating, using the first device, a first protocol message to initiate a refresh of the SIP session with the second device, wherein the first protocol message includes only a header configured with a refresh tag in a header field indicating that the first protocol message is a refresh message that is used to request a status of the SIP session; sending the first protocol message from the first device to the second device; receiving, using the first device and in response to the first protocol message, a second protocol message from the second device, wherein the second protocol message comprises a header and devoid of a body, the header of the second protocol message including the refresh tag and additional information indicating that the second protocol message is in response to the first protocol message; and determining, using the first device and based on the information included in the second protocol message, whether the SIP session is active or inactive.