Granted Patent B2

US 7,593,327 · App. 10/643,005 · Granted Sep 22, 2009

Abstract

Claims (32)

1. A method for compensating for a frequency offset between an ingress local area network and an egress local area network communicating over a transport network, said ingress local area network employing an ingress inter-packet gap between each packet in a packet flow, said method comprising the steps of:

receiving a plurality of packets over said transport network originating from said ingress local area network; and

providing said plurality of received packets to said egress local area network with an egress inter-packet gap between each of said received packets, wherein a size of said egress inter-packet gap is decreased to compensate for said frequency offset when said in said local area network is faster than said egress local area network and is increased to compensate for said frequency offset when said egress local area network is faster than said ingress local area network.

2. The method of claim 1 , wherein a frequency of said ingress local area network exceeds a frequency of said egress local area network and said providing step further comprises the step of reducing said size of said egress inter-packet gap.

3. The method of claim 1 , wherein a frequency of said egress local area network exceeds a frequency of said ingress local area network and said providing step further comprises the step of increasing said size of said egress inter-packet gap.

4. The method of claim 1 , wherein said size of said egress inter-packet gap is statically configured based on said frequency offset.

5. The method of claim 1 , wherein said size of said egress inter-packet gap is dynamically adjusted based on a fill level of a buffer associated with an egress port of said transport network.

6. The method of claim 1 , wherein said size of said egress inter-packet gap is dynamically adjusted to prevent a buffer associated with an egress port of said transport network from overflowing.

7. The method of claim 1 , wherein said size of said egress inter-packet gap is reduced by deleting idle symbols from an extended inter-packet gap.

8. A method for compensating for a frequency of offset between an ingress local area network and an egress local area network communicating over a transport network, said ingress local area network employing an ingress inter-packet gap between each packet in a packet flow, said method comprising the steps of:

receiving a plurality of packets over said transport network originating from said ingress local area network; and

providing said plurality of received packets to said egress local area network with an egress inter-packet gap between each of said received packets, wherein a size of said egress inter-packet gap is less than a size of said ingress inter-packet gap when said ingress local area network is faster than said egress local area network and is greater than a size of said inter-packet gap when said egress local area network is faster than said ingress local area network.

9. The method of claim 8 , wherein said size of said egress inter-packet gap is statically configured based on an expected frequency offset.

10. A method for compensating for a frequency offset between an ingress local area network and an egress local area network communicating over a transport network, said ingress local area network employing an ingress inter-packet gap between each packet in a packet flow, said method comprising the steps of:

buffering a plurality of packets received over said transport network originating from said ingress local area network in an egress buffer;

monitoring a fill level of said egress buffer; and

providing said plurality of received packets to said egress local area network with an egress inter-packet gap between each of said received packets, wherein a size of said egress inter-packet gap is decreased based on said fill level when said ingress local area network is faster than said egress local area network and is increased based on said fill level when said egress local area network is faster than said ingress local area network.

11. The method of claim 10 , wherein said size of said egress inter-packet gap is adjusted to prevent said egress buffer from overflowing.

12. A method for compensating for a frequency offset between an ingress local area network and an egress local area network communicating over a transport network, said ingress local area network employing an ingress inter-packet gap between each packet in a packet flow, said method comprising the steps of:

buffering a plurality of packets received over said transport network originating from said ingress local area network in a first egress buffer;

writing said plurality of packets from said fist egress buffer in a second egress buffer at a rate associated with said transport network together with an inter-packet gap separating each packet; and

providing said plurality of received packets to said egress local area network with an egress inter-packet gap between each of said received packets, wherein a size of said egress inter-packet gap is reduced by deleting one or more idle symbols from said inter-packet gap when said ingress local area network is faster than said egress local area network and is increased by inserting one or more idle symbols in said inter-packet gap when said egress local area network is faster than said ingress local area network.

13. An apparatus for compensating for a frequency offset between an ingress local area network and an egress local area network communicating over a transport network, said ingress local area network employing an ingress inter-packet gap between each packet in a packet flow, said apparatus comprising:

a port for receiving a plurality of packets over said transport network originating from said ingress local area network; and

means for providing said plurality of received packets to said egress local area network with an egress inter-packet gap between each of said received packets, wherein a size of said egress inter-packet gap is decreased to compensate for said frequency offset when said ingress local area network is faster than said egress local area network and is increased to compensate for said frequency offset when said egress local area network is faster than said ingress local area network.

14. The apparatus of claim 13 , wherein a frequency of said ingress local area network exceeds a frequency of said egress local area network and said means for providing further comprises means for reducing said size of said egress inter-packet gap.

15. The apparatus of claim 13 , wherein a frequency of said egress local area network exceeds a frequency of said ingress local area network and wherein means for providing further comprises means for increasing said size of said egress inter-packet gap.

16. The apparatus of claim 13 , wherein said size of said egress inter-packet gap is statically configured based on said frequency offset.

17. The apparatus of claim 13 , wherein said size of said egress inter-packet gap is dynamically adjusted based on a fill level of a buffer associated with an egress port of said transport network.

18. The apparatus of claim 13 , wherein said size of said egress inter-packet gap is dynamically adjusted to prevent a buffer associated with an egress port of said transport network from overflowing.

19. The apparatus of claim 13 , wherein said egress inter-packer gap is inserted by provider equipment between said transport network and said egress local area network.

20. The apparatus of claim 13 , wherein said size of said egress inter-packet gap is reduced by deleting idle symbols from an extended inter-packet gap.

Assignments (9)