Optimal Encoding Multicast Tree using Link Number and Bit

Patent metadata

Field	Value
Publication number	US-2024422092-A1
Application number	US-202418818356-A
Country	US
Kind code	A1
Filing date	Aug 28, 2024
Priority date	Feb 28, 2022
Publication date	Dec 19, 2024
Grant date	—

Abstract

A method implemented by an ingress node in a traffic engineering (TE) multicast domain along a point-to-multipoint (P2MP) path. The method includes receiving a packet from a traffic source; encapsulating the packet with a multicast routing header (MRH) for a sub-tree of the P2MP path through the TE multicast domain, wherein the MRH indicates the sub-tree by encoding link information of one or more links on the sub-tree, the link information of the one or more links comprising a link number of a link from the ingress node to a next hop node or a link bit indicating whether the link corresponding the link number is on the sub-tree; and sending the packet with the MRH toward the next hop node along the sub-tree.

First claim

What is claimed is:

1 . A method implemented by an ingress node in a traffic engineering (TE) multicast domain along a point-to-multipoint (P2MP) path, comprising:
receiving a packet from a traffic source; encapsulating the packet with a multicast routing header (MRH) for a sub-tree of the P2MP path through the TE multicast domain, wherein the MRH indicates the sub-tree by encoding link information of one or more links on the sub-tree, wherein the link information of the one or more links comprises a link number of a link from the ingress node to a next hop node or a link bit indicating whether the link corresponding the link number is on the sub-tree; and sending the packet with the MRH toward the next hop node along the sub-tree.

2 . The method of claim 1 , further comprising determining address of the next hop node from a neighbor address table using the link number of the link, wherein the neighbor address table comprises the address of the next hop node that is a media access control (MAC) address or an Internet Protocol (IP) version 6 (IPv6) address.

3 . The method of claim 1 , wherein the MRH comprises at least one of a link number (Link-No) field for indicating the link number of the link or a link bits field having link bits corresponding to respective link numbers of links, and wherein the link bits indicate whether the links corresponding to the respective link numbers are on the sub-tree.

4 . The method of claim 3 , wherein the MRH further comprises at least one of a number of branches (N-Branches) field for indicating the number of branches from the next hop node of the link along the sub-tree, a size of branches (S-Branches) field, or a field for indicating a pointer pointing to the sub-tree.

5 . The method of claim 3 , wherein the MRH further comprises an L flag indicating whether the next hop node of the link is a leaf node.

6 . The method of claim 3 , wherein the MRH further comprises a B flag with a value indicating that the link bits are used to represent the link information.

7 . The method of claim 3 , wherein the MRH further comprises a flag with a value indicating the link directly from a root of the sub-tree is encoded by the link bits.

8 . The method of claim 3 , wherein the link bits field comprises a Bits field having multiple bits corresponding to respective link numbers, a Plus (P) field with a value indicating that a bit with a first value in the Bits field means a corresponding link is on a branch and the next hop node is a leaf node, and a size of the bits (S-Bits) field indicating a size of the Bits field in a unit.

9 . A method implemented by a transit node in a traffic engineering (TE) multicast domain along a point-to-multipoint (P2MP) path, comprising:
receiving a packet with a multicast routing header (MRH) and a destination address (DA), wherein the MRH indicates a sub-tree from the transit node by encoding first link information of one or more first links on the sub-tree, wherein the first link information of the one or more first links comprises a first link number of a first link from the transit node or a link bit indicating whether the first link corresponding the first link number is on the sub-tree; duplicating a copy of the packet for the sub-tree and determining a next hop node in accordance with the MRH; and sending the copy of the packet toward the next hop node along the sub-tree.

10 . The method of claim 9 , wherein sending the copy of the packet toward the next hop node along the sub-tree comprises sending the copy of the packet with an updated MRH toward the next hop node along the sub-tree, with the updated MRH comprising second link information of one or more second links determined in accordance with the MRH.

11 . The method of claim 9 , further comprising setting a DA of the copy of the packet to address of the next hop node from a neighbor address table using the first link number of the first link from the transit node to the next hop node, wherein the neighbor address table comprises the address of the next hop node that is a media access control (MAC) address or an Internet Protocol (IP) version 6 (IPv6) address.

12 . The method of claim 9 , wherein the MRH comprises at least one of a link number (Link No) field for indicating a link number of a link or a link bits field having multiple bits corresponding to respective link numbers of links, wherein the multiple bits indicate whether the links corresponding to the respective link numbers are on the sub-tree.

13 . The method of claim 12 , wherein the MRH further comprises at least one of a number of branches (N-Branches) field for indicating the number of branches, a size of branches (S-Branches) field, or a field for indicating a pointer pointing to the sub-tree.

14 . The method of claim 13 , wherein the MRH further comprises an L flag with a value indicating that the next hop node is a leaf node and has no corresponding N-Branches field and corresponding S-Branches field.

15 . The method of claim 12 , wherein the first link information further includes a B flag with a value indicating that link bits of the link bits field are used to represent the link information.

16 . The method of claim 12 , wherein the link bits field comprises a Bits field having multiple bits corresponding to respective link numbers, a Plus (P) field with a value indicating that a bit with a first value in the Bits field means a corresponding link is on a branch and the next hop node is a leaf node, and a size of the bits (S-Bits) field with a value indicating a size of the Bits field in a unit.

17 . An ingress node, comprising:
a memory storing instructions; and one or more processors coupled to the memory and configured to execute the instructions to cause the ingress node to:
receive a packet from a traffic source;
encapsulate the packet with a multicast routing header (MRH) for a sub-tree of a point-to-multipoint (P2MP) path through a traffic engineering (TE) multicast domain, wherein the MRH indicates the sub-tree by encoding link information of one or more links on the sub-tree, wherein the link information of the one or more links comprises a link number of a link from the ingress node to a next hop node or a link bit indicating whether the link corresponding the link number is on the sub-tree; and
send the packet with the MRH toward the next hop node along the sub-tree.

18 . The ingress node of claim 17 , wherein the MRH comprises at least one of a link number (Link-No) field for indicating the link number of the link or a link bits field having link bits corresponding to respective link numbers of links, and wherein the link bits indicate whether the links corresponding to the respective link numbers are on the sub-tree.

19 . The ingress node of claim 18 , wherein the MRH further comprises at least one of a number of branches (N-Branches) field for indicating the number of branches from the next hop node of the link along the sub-tree, a size of branches (S-Branches) field, or a field for indicating a pointer pointing to the sub-tree.

20 . The ingress node of claim 18 , wherein the MRH further comprises an L flag indicating whether the next hop node of the link is a leaf node and a B flag with a value indicating that the link bits are used to represent the link information.

Assignees

• Huawei Tech Co Ltd

Inventors

• Chen Huaimo

Classifications

• H04L45/745

  Address table lookup; Address filtering · CPC title

• H04L45/48

  Routing tree calculation · CPC title

• H04L45/488

  using root node determination · CPC title

• H04L45/484

  using multiple routing trees · CPC title

• H04L45/34

  Source routing · CPC title