Abstract: Methods and systems for enhanced domain name system (DNS) response caching are described. An enhanced DNS response caching method includes receiving a connection request for a fully qualified domain name (FQDN). A DNS client checks a local cache for a cached resolved domain name corresponding to the FQDN and sends 3300 a query to obtain or refresh the cached resolved domain name if a Time to Live parameter is expired or about to expire. In response to receiving a negative response or no response for the query, the DNS client determines whether an enhanced DNS response caching parameter is enabled. If the enhanced DNS response caching parameter is enabled, the DNS client sends an expired cached resolved domain name to process the connection request.

Abstract: Various embodiments include computing devices and methods for updating a resource address. A processor of a computing device may receive a request for a resource address from a second computing device. The processor may send to the second computing device the resource address and a time-to-live for the resource address. The processor may determine that the resource address has changed within the time-to-live. The processor may send the changed resource address to the second computing device.

Abstract: Various embodiments include computing devices and methods for updating a resource address. A processor of a computing device may receive a request for a resource address from a second computing device. The processor may send to the second computing device the resource address and a time-to-live for the resource address. The processor may determine that the resource address has changed within the time-to-live. The processor may send the changed resource address to the second computing device.

Abstract: Methods and systems for enhanced domain name system (DNS) response caching are described. An enhanced DNS response caching method includes receiving a connection request for a fully qualified domain name (FQDN). A DNS client checks a local cache for a cached resolved domain name corresponding to the FQDN and sends 3300 a query to obtain or refresh the cached resolved domain name if a Time to Live parameter is expired or about to expire. In response to receiving a negative response or no response for the query, the DNS client determines whether an enhanced DNS response caching parameter is enabled. If the enhanced DNS response caching parameter is enabled, the DNS client sends an expired cached resolved domain name to process the connection request.

Abstract: Methods and systems for enhanced domain name system (DNS) response caching are described. An enhanced DNS response caching method includes receiving a connection request for a fully qualified domain name (FQDN). A DNS client checks a local cache for a cached resolved domain name corresponding to the FQDN and sends 3300 a query to obtain or refresh the cached resolved domain name if a Time to Live parameter is expired or about to expire. In response to receiving a negative response or no response for the query, the DNS client determines whether an enhanced DNS response caching parameter is enabled. If the enhanced DNS response caching parameter is enabled, the DNS client sends an expired cached resolved domain name to process the connection request.

Abstract: Systems, methods, and devices of the various embodiments disclosed herein may enable automatic retry of Internet Protocol (IP) Multimedia Subsystem (IMS) Based Session Initiation Protocol (SIP) Call Setup. Various embodiments may enable a server in an IMS based telecommunication network, such as a proxy-call session control function (P-CSCF) server, interrogating/serving-call session control function (I/S-CSCF) server, telephony application server (TAS), etc., to reattempt SIP call setup. In various embodiments, in response to receiving a SIP error response including a retry-after header, the server may wait a period of time before sending a new SIP invite message.

Abstract: Methods and systems for enhanced domain name system (DNS) response caching are described. An enhanced DNS response caching method includes receiving a connection request for a fully qualified domain name (FQDN). A DNS client checks a local cache for a cached resolved domain name corresponding to the FQDN and sends 3300 a query to obtain or refresh the cached resolved domain name if a Time to Live parameter is expired or about to expire. In response to receiving a negative response or no response for the query, the DNS client determines whether an enhanced DNS response caching parameter is enabled. If the enhanced DNS response caching parameter is enabled, the DNS client sends an expired cached resolved domain name to process the connection request.

Abstract: Systems, methods, and devices of the various embodiments disclosed herein may enable automatic retry of Internet Protocol (IP) Multimedia Subsystem (IMS) Based Session Initiation Protocol (SIP) Call Setup. Various embodiments may enable a server in an IMS based telecommunication network, such as a proxy-call session control function (P-CSCF) server, interrogating/serving-call session control function (I/S-CSCF) server, telephony application server (TAS), etc., to reattempt SIP call setup. In various embodiments, in response to receiving a SIP error response including a retry-after header, the server may wait a period of time before sending a new SIP invite message.

Abstract: Methods and apparatus for allowing users in a group, e.g., family members, to share a telephone number while using different devices, e.g., IP devices, are described. The methods and apparatus allow for users in a group to obtain individual presence information for members of the group by making a single request for presence information corresponding to members of the group. In some embodiments, in response to the single request, the requesting device will be supplied with individual presence information for each member of the group to which the request corresponds. The presence information may be received in individual communications, e.g., one individual message providing presence information on a user of the group. Alternatively presence information for the individual members of the group may be included in a single message that is sent to the requesting device.

Abstract: Methods and apparatus for allowing users in a group, e.g., family members, to share a telephone number while using different devices, e.g., IP devices, are described. The methods and apparatus allow for users in a group to obtain individual presence information for members of the group by making a single request for presence information corresponding to members of the group. In some embodiments, in response to the single request, the requesting device will be supplied with individual presence information for each member of the group to which the request corresponds. The presence information may be received in individual communications, e.g., one individual message providing presence information on a user of the group. Alternatively presence information for the individual members of the group may be included in a single message that is sent to the requesting device.

Abstract: A packet communication system is disclosed that includes an end communication device, a call processing system, and a packet network. To setup up a call from an end user, the end communication device transmits a call request message to the call processing system. The call request message has a header that includes priority information for the call. The call processing system processes the priority information in the header of the call request message to determine if the call request message is for a high priority call. If the call request message is not for a high priority call and the call processing system is in a state of congestion, then the call processing system transmits a response message indicating the state of congestion. Responsive to receiving the response message, the end communication device performs call blocking and provides call treatment to the end user.