Scalable IP-Services Enabled Multicast Forwarding with Efficient Resource Utilization

• US 20100142527A1
• Filed: 02/12/2009
• Published: 06/10/2010
• Est. Priority Date: 09/24/2004
• Status: Active Grant

• Current Assignee: Fortinet Inc.
• Original Assignee: Fortinet Inc.
• Inventors: Balay, Rajesh I., Bhat, Girish, Nagarajan, Rama Krishnan, Lockwood, Gregory
• Granted Patent: US 8,213,347 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/586 of virtual routers
• CPC Class Codes: H04L 45/60 Router architectures
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06

Abstract

Methods and apparatus are provided for managing multicast Internet Protocol (IP) flows. According to one embodiment, a multicast IP flow is identified at an interface of a network device using information from a packet header. For any newly identified multicast IP flow, if flow-specific services are required, a new first transmit control block (TCB), which includes one or more attributes relating to flow-specific services required by the newly identified multicast IP flow, is created for the newly identified multicast IP flow. Otherwise, if flow-specific services are not required by the newly identified multicast IP flow, a default second TCB, which excludes any attributes relating to flow-specific services and which includes one or more attributes related to a virtual interface (VI) serving as an outbound interface (OIF) for the newly identified multicast IP flow, is used.

Claims

1. A method of managing multicast Internet Protocol (IP) flows, the method comprising:

identifying a multicast IP flow at an interface of a network device using information from a packet header;

for any newly identified multicast IP flow, if flow-specific services are required for the newly identified multicast IP flow, then creating for the newly identified multicast IP flow at least one new first transmit control block (TCB), which includes one or more attributes relating to flow-specific services required by the newly identified multicast IP flow; and

if flow-specific services are not required by the newly identified multicast IP flow, then using for the newly identified multicast IP flow a default second TCB, which excludes any attributes relating to flow-specific services and which includes one or more attributes related to a virtual interface (VI) serving as an outbound interface (OIF) for the newly identified multicast IP flow.

2. The method of claim 1, in which the flow-specific services include Access Control List (ACL) based services.

3. The method of claim 1, wherein said identifying a multicast IP flow at an interface of a network device using information from a packet header includes using a source IP address and a destination IP address portion of the packet header to classify the multicast IP flow.

4. The method of claim 3, wherein additional portions of the packet header are used to further classify the multicast IP flow in accordance with appropriate services.

5. A multimode multicast forwarding protocol, comprising:

a first mode, in which each flow of a multicast session identified by an interface of a plurality of interfaces of a network device uses a default transmit control block (TCB) that excludes any attributes relating to flow-specific services; and

a second mode, in which each flow of a multicast session identified by one of the plurality of interfaces uses only one of (1) a first TCB that includes at least one attribute relating to a flow-specific service; and

(2) a second TCB that excludes any attributes relating to flow-specific services, and wherein the second TCB is shared across all flows without flow-specific services enabled that are present in a common or a different multicast session.

6. The method of claim 5, in which the first TCB includes at least one other attribute relating to any services on an outbound interface (OIF) of the network device that are not flow-specific.

7. A program storage device readable by one or more processors of a router, the program storage device tangibly embodying a program of instructions executable by the one or more processors of the router to perform method steps for managing multicast Internet Protocol (IP) flows, the method steps comprising:

identifying a multicast IP flow at an interface of the router using information from a packet header of a packet received on the interface;

for any newly identified multicast IP flow, if flow-specific services are required for the newly identified multicast IP flow, then creating for the newly identified multicast IP flow at least one new first transmit control block (TCB), which includes one or more attributes relating to flow-specific services required by the newly identified multicast IP flow; and

if flow-specific services are not required by the newly identified multicast IP flow, then using for the newly identified multicast IP flow a default second TCB, which excludes any attributes relating to flow-specific services and which includes one or more attributes related to a virtual interface (VI) serving as an outbound interface (OIF) for the newly identified multicast IP flow.