Browse Prior Art Database

INVITE-based resource reservation for multi-codec offer

IP.com Disclosure Number: IPCOM000132038D
Original Publication Date: 2005-Nov-29
Included in the Prior Art Database: 2005-Nov-29
Document File: 3 page(s) / 47K

Publishing Venue

Motorola

Related People

Jheroen Dorenbosch: INVENTOR [+2]

Abstract

An intermediate entity in an IP network, like a base station, inspects the codec information an INVITE message for a high Quality of Service session and does resource reservation and/or Session Access Control, exclusively based on the information in the INVITE and in the OK messages.

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This is the abbreviated version, containing approximately 43% of the total text.

INVITE-based resource reservation for multi-codec offer

CE13718N (28431)  Jheroen Dorenbosch, Anatoly Agulnik.

Abstract:  An intermediate entity in an IP network, like a base station, inspects the codec information an INVITE message for a high Quality of Service session and does resource reservation and/or Session Access Control, exclusively based on the information in the INVITE and in the OK messages.

Future and current system will use SIP for session setup.  To get good Quality of Service, resource reservation and Call Access Control is needed.  A call should only be allowed when sufficient resources are available. 

Resource allocation includes codec negotiation during the INVITE message sequence that is used to set up a call.  Normally one or more codecs are offered in the initial INVITE message.  However, the initial INVITE may sometimes not contain any codec information and the codec must be negotiated in the later stages of the call setup. 

RFC 3312 discusses a resource reservation method that can handle a multi-codec offer in an INVITE.  This method waits until the codec choice has been resolved, which results in a late resource reservation, and requires additional messages that slow down the call setup.  The method of RFC 3312 is shown below:

               |                                            |

               |-------------(1) INVITE SDP1--------------->|

               |<------(2) 183 Session Progress SDP2--------|

               |  ***                                 ***   |

               |--*R*-----------(3) PRACK-------------*R*-->|

               |  *E*                                 *E*   |

               |<-*S*-------(4) 200 OK (PRACK)--------*S*---|

               |  *E*                                 *E*   |

               |  *R*                                 *R*   |

               |  *V*                                 *V*   |

               |  *A*                                 *A*   |

               |  *T*                                 *T*   |

               |  *I*                                 *I*   |

               |  *O*                                 *O*   |

               |  *N*                                 *N*   |

               |  ***                                 ***   |

               |  ***                  ...