Mapping of packets between links of trunk groups using Mux/Demux devices

• US 6,788,682 B1
• Filed: 08/02/2000
• Issued: 09/07/2004
• Est. Priority Date: 08/02/2000
• Status: Expired due to Fees

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Kimmitt, Myles
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): NGUYEN, TOAN D
• Application Number:
  US09/630,492
• Time in Patent Office: 1,497 Days
• Field of Search: H04/L 1.256, H04/L 1.226, H04/L 1.244, 370/422, 370/396, 370/464, 370/392, 370/468, 370/351, 370/445, 370/446, 370/389, 370/423, 370/395.31, 370/229, 370/216, 709/105, 709/226
• US Class Current: 370/389
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/502 Frame based

Abstract

A method and apparatus for mapping packets received over a first trunk group comprising n links to a second trunk group comprising m links. A first Mux/Demux device receives packets over the n communication links at n corresponding input ports. The first Mux/Demux device inserts within each received packet a port identifier tag that identifies the port on which the respective packet is received. The packets are transmitted over a communications link for receipt by a second Mux/Demux device. The second Mux/Demux device has m output ports for communicating over the m links of the second trunk group. A port translation table is maintained at the second Mux/Demux devices. The port translation table is indexed by the port identifier tag within the received packets to identify which of the m output ports of the second Mux/Demux device should be employed for transmission of the respective packet. Each packet is transmitted out of the corresponding port identified within the port translation table.

Claims

1. A method for identifying one of a plurality of output ports of a first Mux/Demux device coupled to corresponding first communication links confirmed as a first trunk group for transmission of a packet received from a second Mux/Demux device having a plurality of input ports coupled to corresponding second communication links configured as a second trunk group, the number of input ports of said second Mux/Demux device associated with said second trunk group exceeding the number of output ports of said first Mux/Demux device associated with said first trunk group, said method comprising:

storing in a port translation table output port identifiers in a round robin sequence indexed by port identifier tags;

receiving at said first Mux/Demux device from said second Mux/Demux device via a communication path, a packet having a preamble containing one of said port identifier tags that identifies one input port of said plurality of second Mux/Demux device input ports on which the respective packet was received;

identifying one of said plurality of output ports of said first Mux/Demux device for transmission of said packet from said port translation table indexed by said one of said port identifier tags;

disassociating said one of said port identifier tags from said packet; and

transmitting said packet out of said first Mux/Demux device from the port specified by said port translation table.

2. A method for identifying one of a plurality of output ports of a first Mux/Demux device coupled to corresponding first communication links configured as a first trunk group for transmission of a packet received from a second Mux/Demux device having a plurality of input ports coupled to corresponding second communication links configured as a second trunk group, the number of input ports of said second Mux/Demux device associated with said second trunk group exceeding the number of output ports of said first Mux/Demux device associated with said fit trunk group, said method comprising:

storing in a port translation table in a round robin sequence output port identifiers identifying said output ports associated with said first trunk group indexed by port identifier tags i times, where i is an integer, and hashing any remaining port identifier tags across all available output ports of said first Mux/Demux device associated with said first trunk group

receiving at said first Mux/Demux device from said second Mux/Demux device via a communication path, a packet having a preamble containing one of said port identifier tags that identifies one input port of said plurality of second Mux/Demux device input ports on which the respective packet was received;

identifying one of said plurality of output ports of said first Mux/Demux device for transmission of said packet from said port translation table indexed by said one of said port identifier tags;

disassociating said one of said port identifier tags from said packet; and

transmitting said packet out of said first Mux/Demux device from the port specified by said port translation table.

3. A method for generating a port translation table within a first Mux/Demux device having a plurality of output ports associated with a first trunk group, said method comprising the steps of:

receiving a plurality of packets at said first Mux/Demux device from a second Mux/Demux device having a plurality of input ports corresponding to ports of a second bunk group, wherein each of said packets has an associated port identifier tag that identifies one input port of said plurality of second Mux/Demux device input ports on which the respective packet was received;

detecting a largest port identifier mag of said plurality of received port identifier tags to identify the number of ports within said second trunk group;

ascertaining the number of output ports within said plurality of output ports to determine the size of said first trunk group; and

configuring said port translation table in accordance with a mapping technique selected based upon the relative sizes of said second trunk group and said first trunk group.

4. The method of claim 3 wherein said configuring step includes the step of storing in said port translation table a unique output port identifier that is indexed by each port identifier tag in the event the number of input ports of said second Mux/Demux device associated with said second trunk group equals the number of output ports of said first Mux/Demux device associated with said first trunk group.

5. The method of claim 3 wherein said configuring step includes the step of storing in said port translation table said output port identifiers in a round robin sequence indexed by said port identifier tags in the event the number of input ports of said second Mux/Demux device associated with said second trunk group exceeds the number of output ports of said first Mux/Demux device associated with said first trunk group.

6. The method of claim 3 wherein said configuring step includes the step of storing in said port translation table, in a round robin sequence, output port identifiers associated with said first Mux/Demux device output ports, wherein said output port identifiers are stored in said table i times, where i is a specified integer, and each of said output port identifiers is indexed by one of said port identifier tags, and hashing any remaining port identifier tags across said plurality of output ports of said first Mux/Demux device in the event the number of input ports of said second Mux/Demux device associated with said second trunk group exceeds the number of output ports of said first Mux/Demux device associated with said first trunk group.

7. A method for identifying one of a plurality of output ports of a first Mux/Demux device coupled to corresponding first communication links configured as a first trunk group for transmission of a packet received from a second Mux/Demux device having a plurality of input ports coupled to corresponding second communication links configured as a second trunk group, the number input ports of said second Mux/Demux device being less than the number of output ports of said first Mux/Demux device, said method comprising:

receiving at said first Mux/Demux device from said second Mux/Demux device via a communication path, a packet having a preamble containing a port identifier tag that identifies one input port of said plurality of second Mux/Demux device input ports through which the respective packet was received;

selecting one of said plurality of output ports of said first Mux/Demux device for transmission of said packet, based on at least in part of said port identifier tag, wherein said selecting comprises distributing packets received through said plurality of input ports across said plurality of output ports;

disassociating said port identifier tag from said packet; and

transmitting said packet out of said first Mux/Demux device from the selected one of said plurality of output ports.