Provisional IP-aware virtual paths over networks

• US 7,046,665 B1
• Filed: 10/26/1999
• Issued: 05/16/2006
• Est. Priority Date: 10/26/1999
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Extreme Networks, Inc.
• Inventors: Walrand, Jean, Gupta, Rajarshi, Fawaz, Ayman
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): Phan, Tri H
• Application Number:
  US09/427,215
• Time in Patent Office: 2,394 Days
• Field of Search: 370/395.5, 370/395.52, 370/395.53, 370400-401, 370/412, 370/428, 370465-466, 370/469, 370/351, 370/352, 370/355, 398/48, 398/68, 398/79
• US Class Current: 370/392
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 49/555 Error detection
• CPC Class Codes: H04L 49/602 Multilayer or multiprotocol switching, e.g. IP switching
• CPC Class Codes: H04L 49/606 Hybrid ATM switches, e.g. ATM&STM, ATM&Frame Relay or ATM&IP

Abstract

In accordance with the invention, a system and method for providing QoS to packets formatted in accordance with one protocol (e.g., IP or Ethernet) carried over networks that are originally designed to be used with another protocol (e.g., ATM, WDM, or TDM). In one embodiment of the invention, such a switch is modified in order to allow the switch to become “IP-aware.” Such a modified switch can identify IP packets, determine if any packets should be dropped, classify the packets with a queue, and schedule the packets of each queue in a manner that provides quality of service to the packets in the queue. Moreover, some embodiments of a modified switch further include a monitor to keep statistics on the packets in the modified switch, a protection mechanism that monitors fault information for at least part of the network, and a provisioning mechanism that determines normal and backup paths for each connection.

Claims

1. A switch comprising:

a classification module to classify packets according to information contained in a header of a packet;

a packet identifier coupled to the classification module to identify packets formatted in accordance with an Ethernet Protocol and to further determine whether to send or discard each packet;

a switching fabric coupled to the packet identifier to operate in accordance with a Wavelength Division Multiplexing (WDM) protocol and to place packets into an appropriate queue based at least in part on each packet'"'"'s classification;

a scheduling module coupled to the switching fabric to schedule the packets for transmission and to provide Quality of Service (QoS) to the packets; and

a control module coupled to the classification module, the packet identifier, and the scheduling module to control the functions of each module and to select a next appropriate link for packet transmission based on information about faults in the network.

2. A method for identifying Internet Protocol (IP) packets in a switch designed for use with an Asynchronous Transfer Mode (ATM) protocol comprising:

identifying an IP packet by reading a bit in an ATM header of an ATM cell;

detecting an IP header of the IP packet in a next ATM cell;

determining whether the IP packet is a user data protocol (UDP) packet or a transmission control protocol (TCP) packet;

determining whether to drop or transmit the IP packet based on whether the IP packet is a UDP or TCP packet by tracking the number of packets that arrive at the switch, and dropping a TCP packet based on the tracked number;

classifying the IP packet into one of a plurality of quality of service (QoS) classes to provide an appropriate level of QOS; and

forwarding the IP packet in accordance with the appropriate level of QoS.

3. The method of claim 2, further comprising dropping ATM cells that contain a part of the IP packet if the IP packet has been determined to be dropped.

4. The method of claim 2, wherein determining whether the IP packet should be dropped further comprises determining whether a buffer of the switch is full and dropping a UDP packet if the buffer is full.

5. An apparatus comprising:

a network interface to receive a plurality of packets from a network;

a processor and logic executable thereon to provide a protocol architecture for processing the received packets, the protocol architecture including

a queuing layer to identify packets formatted in accordance with an Internet Protocol (IP) and to determine whether to transmit or drop each packet;

a classification layer to classify the identified packets for Quality of Service (QoS) and to determine to which of a plurality of queues the packets belong;

a scheduling layer to allocate link bandwidth to the plurality of queues;

a protection layer to select the next appropriate link for packet transmission based on information about faults in the network; and

a control plane to perform provisioning and to monitor each layer.