| 摘要 |
The method comprising, reading or parsing an opaque parameter in the header fields of received session initiation protocol (SIP) messages, ascertaining a priority based on the opaque parameter and controlling the forwarding of the SIP message with this identified priority. The priority may be determined by the outcome of an operation on or comparison of the opaque parameter and a further parameter such as the Cseq number. The opaque parameter may be based upon the value of a Cseq number and may be applied to outbound SIP messages. In one embodiment the apparatus may be a session border controller (SBC) 11 which prioritises the passing on of SIP REGISTER messages from a SIP device 15 to a Registrar server 13. The SBC 11 can prevent the Registrar server 13 becoming overloaded, congested or crashing especially when multiple registration requests occur substantially simultaneously such as after a power outage. |
