Switching apparatus having universal transport of data packet frames
Apparatus is dedicated to switching data packet frames of different types coming from at least two transport networks that use different transport protocol layers. Said apparatus includes a switching module and at least two access cards, each of which is connected to a respective one of said networks and to said switching module, each access card including processing means that, when they receive a frame coming from a source network to which they are connected and for a destination network, have the tasks of removing from said frame the transport protocol layers that it contains, and then of adding an internal header to the payload data of at least one packet of said frame, prior to transmitting it to said switching module, said internal header comprising at least: a channel identifier field containing a value representative of a channel assigned to the connection used by said frame on being set up; a length field containing a value representative of the number of bytes contained in the packet in question; and a type field containing values representative of characteristics of the payload data of the packet in question.
1. An apparatus for switching data packet frames of different types coming from at least two transport networks that use different transport protocol layers, said apparatus comprising:
a switching module;
at least two access cards,
each of which is connected to a respective one of said networks and to said switching module,
each access card including processing means arranged so that, on receiving a frame coming from a source network to which they are connected and for a destination network, they remove from said frame the transport protocol layers that it contains;
said apparatus being characterized in that it further comprises means for adding an internal header to the payload data of at least one packet of said frame, prior to transmitting it to said switching module,
said internal header comprising at least i) a channel identifier field containing a value representative of a channel assigned to the connection used by said frame on being set up, ii) a length field containing a value representative of the number of bytes contained in said packet, and iii) a type field containing values representative of characteristics of the payload data of said packet; and
a transcoder card connected to said switching module and arranged so that, on receiving a frame coming from an access card, via said switching module, and for another access card, and including at least one internal header added to at least one payload data packet presenting first coding, it converts said first coding of the payload data into second coding, and then it transmits said frame to said switching module in order to transmit it to said other access card.
2. Apparatus according to claim 1 , characterized in that said processing means are arranged so as to integrate into each internal header a sequence field containing a value representative of a time interval between packets and of a sequence number of the packet to which said internal header is added.
3. Apparatus according to claim 1 , characterized in that said processing means are arranged so as to integrate into each internal header an aggregation field containing a value indicating whether said packet is the last in a sequence of related packets.
4. Apparatus according to claim 1 , characterized in that said processing means are arranged so as to add an internal header to each packet contained in a frame.
5. Apparatus according to claim 1 , characterized in that said processing means are arranged so that, on receiving a frame coming from said switching module and including at least one internal header, they remove from said frame said internal header that it contains, and they then add to said frame transport protocol layers that are chosen as a function of the values of the fields of said internal header and as a function of said destination network, prior to transmitting it over the connection defined by the value of the channel identifier field of said internal header.
6. Apparatus according to claim 1 , characterized in that said switching module is arranged so that, when no coding conversion is to be performed, it causes each frame including at least one added internal header to transit via said transcoder card, during a preliminary protocol negotiation phase.
7. Apparatus according to claim 1 , characterized in that said switching module is arranged so that, when no coding conversion is to be performed, it switches a frame directly without causing it to transit via said transcoder card, outside any preliminary protocol negotiation phase.
8. Apparatus according to claim 1 , characterized in that said characteristics of the payload data of a packet are chosen from among a group comprising at least a type of coding of the payload data, a mode of coding for a type of coding in question, a packet time for the packet in question, a type of payload data of the packet in question, and a type of source network.
9. Network equipment for at least two transport networks that use different transport protocol layers, said network equipment comprising:
a switching apparatus having capability of switching data packet frames of different types coming from at least two transport networks that use different transport protocol layers, said apparatus comprising:
a switching module;
at least two access cards, each of which is connected to a respective one of said networks and to said switching module,
each access card including processing means arranged so that, on receiving a frame coming from a source network to which they are connected and for a destination network, they remove from said frame the transport protocol layers that it contains;
said apparatus being characterized in that it further comprises means for adding an internal header to the payload data of at least one packet of said frame, prior to transmitting it to said switching module,
said internal header comprising at least a channel identifier field containing a value representative of a channel assigned to the connection used by said frame on being set up, a length field containing a value representative of the number of bytes contained in said packet, and a type field containing values representative of characteristics of the payload data of said packet; and
a transcoder card connected to said switching module and arranged so that, on receiving a frame coming from an access card, via said switching module, and for another access card, and including at least one internal header added to at least one payload data packet presenting first coding, it converts said first coding of the payload data into second coding, and then it transmits said frame to said switching module in order to transmit it to said other access card.
10. Equipment according to claim 9 , characterized in that it is chosen from a group comprising at least a voice/media gateway, a base station controller, an SGSN-type node, and a GGSN-type node.
11. An apparatus for switching data packet frames of different types coining from at least two transport networks that use different transport protocol layers, said apparatus comprising:
a switching module;
at least two access cards, each of which is connected to a respective one of said networks and to said switching module,
each access card including processing means arranged so that, on receiving a frame coming from a source network to which they are connected and for a destination network, they remove from said frame the transport protocol layers that it contains;
said apparatus being characterized in that it further comprises means for adding an internal header to the payload data of at least one packet of said frame, prior to transmitting it to said switching module,
said internal header comprising a channel identifier field containing a value representative of a channel assigned to the connection used by said frame on being set up, a length field containing a value representative of the number of bytes contained in said packet, and a type field containing values representative of characteristics of the payload data of said packet; and
a transcoder card connected to said switching module and arranged so that, on receiving a frame coming from an access card, via said switching module, and for another access card, and including at least one internal header added to at least one payload data packet presenting first coding, it converts said first coding of the payload data into second coding, and then it transmits said frame to said switching module in order to transmit it to said other access card,
wherein said switching module is arranged so that, when no coding conversion is to be performed, it causes each frame including at least one added internal header to transit via said transcoder card, during a preliminary protocol negotiation phase and
wherein said switching module is arranged so that, when no coding conversion is to be performed, it switches a frame directly without causing it to transit via said transcoder card, outside any preliminary protocol negotiation phase.
12. Apparatus according to claim 11 , characterized in that said processing means are arranged so as to integrate into each internal header a sequence field containing a value representative of a time interval between packets and of a sequence number of the packet to which said internal header is added.
13. Apparatus according to claim 11 , characterized in that said processing means are arranged so as to integrate into each internal header an aggregation field containing a value indicating whether said packet is the last in said packet in question.
14. Apparatus according to claim 11 , characterized in that said processing means are arranged so as to add an internal header to each packet contained in a frame.
15. Apparatus according to claim 11 , characterized in that said processing means are arranged so that, on receiving a frame coming from said switching module and including at least one internal header, they remove from said frame said internal header that it contains, and they then add to said frame transport protocol layers that are chosen as a function of the values of the fields of said internal header and as a function of said destination network, prior to transmitting it over the connection defined by the value of the channel identifier field of said internal header.
16. Apparatus according to claim 11 , characterized in that said characteristics of the payload data of a packet are chosen from among a group comprising at least a type of coding of the payload data, a mode of coding for a type of coding in question, a packet time for the packet in question, a type of payload data of the packet in question, and a type of source network.