# US 10,313,216 B2 · Bit-forwarding ingress router, bit-forwarding router, and operation, administration and maintenance test method

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- Number: US 10,313,216 B2
- Document ID: US10313216B2
- Status: Granted
- Kind: B2
- Application number: 15/639,896
- Filed: 2017-06-30
- Published: 2017-10-19
- Granted: 2019-06-04
- Earliest claimed: 2014-12-30
- Assignees: Huawei Technologies Co., Ltd.
- Applicants: Huawei Technologies Co., Ltd.
- Inventors: Lianshu Zheng; Guoyi Chen
- Web page: https://patentgrep.com/patent/US10313216B2

## CPC

- H04L 43/08: Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters
- H04L 43/0811: by checking connectivity
- H04L 43/00: Arrangements for monitoring or testing data switching networks
- H04L 45/16: Multipoint routing
- H04L 45/20: {Hop count for routing purposes, e.g. TTL}
- H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS]
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

Embodiments of this application provide a bit-forwarding ingress router, a bit-forwarding router, and an OAM test method, and pertain to the field of multicast networks. A first BFR receives an OAM request packet from a BFIR; the first BFR determines, according to the OAM request packet, that a destination BFR corresponding to the OAM request packet is the first BFR; and the first BFR obtains a first OAM response packet according to an ID of the BFIR, and sends the first OAM response packet to the BFIR. According to the method and the apparatus that are provided in the embodiments of this application, a problem that a BFIR cannot diagnose or handle a transmission fault when the fault occurs during transmission of a multicast packet can be resolved, which helps implement connectivity testing by using an OAM packet and enables testing of multiple BFERs.

## Claims

### Claim 1

A bit-forwarding ingress router (BFIR) in a bit indexed explicit replication (BIER)-based network, the router comprising:
a network interface; a memory storing instructions; and
a processor coupled to the memory to execute the instructions to:
obtain a first operation, administration and maintenance (OAM) request packet according to an identifier (ID) of at least one bit-forwarding egress router (BFER), wherein the first OAM request packet comprises an ID of the BFIR, a set identifier, and a bit string corresponding to the at least one BFER, wherein the set identifier corresponds to the at least one BFER, and the first OAM request packet is used for testing a link between the BFIR and the at least one BFER; and
send the first OAM request packet to the at least one BFER using the network interface.

### Claim 2 (depends on 1)

The BFIR according to claim 1, wherein the processor executes the instructions to:
obtain the set identifier and the bit string according to the ID of the at least one BFER;
obtain a second OAM request packet according to the bit string, wherein a packet header of the second OAM request packet comprises the bit string and the ID of the BFIR, and a payload of the second OAM request packet comprises an OAM packet; and
obtain the first OAM request packet by inserting a first bit indexed explicit replication multiprotocol label switching (BIER-MPLS) label into the second OAM request packet according to the set identifier, wherein the first BIER-MPLS label comprises a label corresponding to the set identifier.

### Claim 3 (depends on 1)

The BFIR according to claim 1, wherein:
the first OAM request packet is used for connectivity testing on a link between the BFIR and a first bit-forwarding router (BFR);
the first BFR is a device on the link between the BFIR and the at least one BFER; and
the processor further executes the instructions to:
determine a first time-to-live (TTL), wherein a value of the first TTL is M, and M is used to identify a hop count before the first OAM request packet arrives at the first BFR from the BFIR, and
add the first TTL into the first OAM request packet.

### Claim 4 (depends on 3)

The BFIR according to claim 3, wherein the processor further executes the instructions to:
receive a first OAM response packet from the first BFR, wherein the first OAM response packet comprises an ID of a third BFR, a set identifier corresponding to the BFIR, and a bit string corresponding to the BFIR, and the third BFR is a previous hop of the first BFR on the link between the BFIR and the at least one BFER;
obtain a second TTL according to the first OAM response packet and the first TTL, wherein a value of the second TTL is a result of adding a preset value to the value of the first TTL;
obtain a third OAM request packet by inserting a second BIER-MPLS label into the second OAM request packet according to the second TTL and the set identifier, wherein the second BIER-MPLS label comprises the label corresponding to the set identifier and the second TTL, the third OAM request packet is used for testing a link between the BFIR and a second BFR, and the second BFR is a next hop of the first BFR on the link between the BFIR and the at least one BFER; and
send the third OAM request packet to the first BFER.

### Claim 5 (depends on 1)

The BFIR according to claim 1, wherein the at least one BFER comprises the first BFER, and wherein the processor further executes the instructions to:
receive an OAM response packet from the first BFER, wherein the OAM response packet comprises an ID of the first BFER, the set identifier corresponding to the BFIR, and the bit string corresponding to the BFIR.

### Claim 6

A first bit-forwarding router (BFR) in a bit indexed explicit replication (BIER)-based network, the router comprising:
a network interface; a memory storing instructions; and
a processor coupled to the memory to execute the instructions to:
receive an operation, administration and maintenance (OAM) request packet from a bit-forwarding ingress router (BFIR) using the network interface, wherein the OAM request packet comprises an identifier (ID) of the BFIR, a set identifier corresponding to at least one bit-forwarding egress router (BFER), and a bit string corresponding to the at least one BFER, and the OAM request packet is used for testing a link between the BFIR and the at least one BFER;
determine, according to the OAM request packet, that a destination BFR corresponding to the OAM request packet is the first BFR;
obtain a first OAM response packet according to the ID of the BFIR, wherein the first OAM response packet comprises an ID of the first BFR, a set identifier corresponding to the BFIR and a bit string corresponding to the BFIR; and
send the first OAM response packet to the BFIR using the network interface.

### Claim 7 (depends on 6)

The first BFR according to claim 6, wherein the first BFR is a BFER among the at least one BFER, and wherein the processor executes the instructions to:
determine, according to the set identifier and the bit string that are comprised in the OAM request packet, that the at least one BFER comprises the first BFR; and
determine that the destination BFR corresponding to the OAM request packet is the first BFR.

### Claim 8 (depends on 7)

The first BFR according to claim 7, wherein the OAM request packet further comprises a type length value (TLV), and the TLV is used to carry the set identifier, the bit string, and a length of the bit string, and wherein the processor further executes the instructions to:
determine, according to the TLV comprised in the OAM request packet, that the at least one BFER comprises the first BFR; and
verify that the destination BFR of the OAM request packet is the first BFR.

### Claim 9 (depends on 8)

The first BFR according to claim 8, wherein the processor further executes the instructions to:
obtain an ID of the at least one BFER according to the set identifier, the bit string, and the length of the bit string that are carried in the TLV;
check whether an ID of the first BFR is comprised in the ID of the at least one BFER; and
in response to the ID of the first BFR being comprised in the ID of the at least one BFER, determine that the at least one BFER comprises the first BFR.

### Claim 10 (depends on 6)

The first BFR according to claim 6, wherein:
the first BFR is a BFR on the link between the BFIR and the at least one BFER;
a packet header of the OAM request packet comprises a time-to-live (TTL); and
the processor further executes the instructions to:
decrease a value of the TTL by a preset value,
determine that the value of the TTL obtained after the preset value is deducted reaches 0, and
determine that the destination BFR corresponding to the OAM request packet is the first BFR.

### Claim 11 (depends on 10)

The first BFR according to claim 10, wherein the processor further executes the instructions to:
determine that the value of the TTL obtained after the preset value is deducted does not reach 0;
determine that the destination BFR corresponding to the OAM request packet is not the first BFR; and
forward the OAM request packet to the at least one BFER.

### Claim 12 (depends on 6)

The first BFR according to claim 6, wherein the processor executes the instructions to:
obtain, according to the ID of the BFIR, the set identifier and the bit string corresponding to the BFIR;
obtain a second OAM response packet according to the bit string corresponding to the BFIR, wherein a packet header of the second OAM response packet comprises the bit string and the ID of the first BFR, and a payload of the second OAM response packet comprises an OAM packet; and
obtain the first OAM response packet by inserting a third bit indexed explicit replication multiprotocol label switching (BIER-MPLS) label into the second OAM response packet according to the set identifier corresponding to the BFIR, wherein the third BIER-MPLS label comprises a label corresponding to the set identifier corresponding to the BFIR.

### Claim 13 (depends on 12)

The first BFR according to claim 12, wherein the processor further executes the instructions to:
obtain an ID of a second BFR, wherein the second BFR is a previous hop of the first BFR on the link between the BFIR and the at least one BFER; and
add the ID of the second BFR into the payload of the second OAM response packet.

### Claim 14

An operation, administration and maintenance (OAM) test method, used in a bit indexed explicit replication (BIER)-based network, the method comprising:
obtaining, by a bit-forwarding ingress router (BFIR), a first OAM request packet according to an identifier (ID) of at least one bit-forwarding egress router (BFER), wherein the first OAM request packet comprises an ID of the BFIR, a set identifier, and a bit string corresponding to the at least one BFER, wherein the set identifier corresponds to the at least one BFER, and the first OAM request packet is used for testing a link between the BFIR and the at least one BFER; and
sending, by the BFIR, the first OAM request packet to the at least one BFER.

### Claim 15 (depends on 14)

The method according to claim 14, wherein the obtaining, by a BFIR, a first OAM request packet according to an ID of at least one BFER comprises:
obtaining, by the BFIR, the set identifier and the bit string according to the ID of the at least one BFER;
obtaining, by the BFIR, a second OAM request packet according to the bit string, wherein a packet header of the second OAM request packet comprises the bit string and the ID of the BFIR, and a payload of the second OAM request packet comprises an OAM packet; and
obtaining, by the BFIR, the first OAM request packet by inserting a first bit indexed explicit replication multiprotocol label switching (BIER-MPLS) label into the second OAM request packet according to the set identifier, wherein the first BIER-MPLS label comprises a label corresponding to the set identifier.

### Claim 16 (depends on 14)

The method according to claim 14, wherein the first OAM request packet is used for testing a link between the BFIR and a first BFR, and the first BFR is a device on the link between the BFIR and the at least one BFER; and
the obtaining, by a BFIR, a first operation, administration and maintenance OAM request packet according to an identifier ID of at least one bit-forwarding egress router BFER further comprises:
determining, by the BFIR, a first time-to-live (TTL), wherein a value of the first TTL is M, and M is used to identify a hop count before the first OAM request packet arrives at the first BFR from the BFIR; and
adding, by the BFIR, the first TTL into the first OAM request packet.

### Claim 17 (depends on 16)

The method according to claim 16, further comprising:
receiving, by the BFIR, a first OAM response packet from the first BFR, wherein the first OAM response packet comprises an ID of a third BFR, a set identifier corresponding to the BFIR, and a bit string corresponding to the BFIR, and the third BFR is a previous hop of the first BFR on the link between the BFIR and the at least one BFER;
obtaining, by the BFIR, a second TTL according to the first OAM response packet and the first TTL, wherein a value of the second TTL is a result of adding a preset value to the value of the first TTL;
obtaining, by the BFIR, a third OAM request packet by inserting a second BIER-MPLS label into the second OAM request packet according to the second TTL and the set identifier, wherein the second BIER-MPLS label comprises the label corresponding to the set identifier and the second TTL, the third OAM request packet is used for testing a link between the BFIR and a second BFR, and the second BFR is a next hop of the first BFR on the link between the BFIR and the at least one BFER; and
sending, by the BFIR, the third OAM request packet to the second BFR.

### Claim 18 (depends on 14)

The method according to claim 14, wherein the at least one BFER comprises a first BFER, and the method further comprises:
receiving, by the BFIR, an OAM response packet from the first BFER, wherein the OAM response packet comprises an ID of the first BFER, the set identifier corresponding to the BFIR, and the bit string corresponding to the BFIR.

### Claim 19

An operation, administration and maintenance (OAM) test method, used in a bit indexed explicit replication BIER-based network, the method comprising:
receiving, by a first bit-forwarding router (BFR), an OAM request packet from a bit-forwarding ingress router (BFIR), wherein the OAM request packet comprises an identifier (ID) of the BFIR, a set identifier, and a bit string corresponding to at least one BFER, wherein the set identifier corresponds to the at least one BFER, and the OAM request packet is used for testing a link between the BFIR and the at least one BFER;
determining, by the first BFR according to the OAM request packet, that a destination BFR corresponding to the OAM request packet is the first BFR;
obtaining, by the first BFR, a first OAM response packet according to the ID of the BFIR, wherein the first OAM response packet comprises an ID of the first BFR, a set identifier corresponding to the BFIR, and a bit string corresponding to the BFIR; and
sending, by the first BFR, the first OAM response packet to the BFIR.

### Claim 20 (depends on 19)

The method according to claim 19, wherein the first BFR is a BFER among the at least one BFER, and the determining, by the first BFR according to the OAM request packet, that a destination BFR corresponding to the OAM request packet is the first BFR comprises:
determining, by the first BFR according to the set identifier and the bit string that are comprised in the OAM request packet, that the at least one BFER comprises the first BFR; and
determining, by the first BFR, that the destination BFR corresponding to the OAM request packet is the first BFR.

### Claim 21 (depends on 20)

The method according to claim 20, wherein the OAM request packet further comprises a type length value (TLV), and the TLV is used to carry the set identifier, the bit string, and a length of the bit string; and
before the obtaining, by the first BFR, a first OAM response packet according to the ID of the BFIR, the method further comprises:
determining, by the first BFR according to the TLV comprised in the OAM request packet, that the at least one BFER comprises the first BFR; and
verifying, by the first BFR, that the destination BFR of the OAM request packet is the first BFR.

### Claim 22 (depends on 21)

The method according to claim 21, wherein the determining, by the first BFR according to the TLV comprised in the OAM request packet, that the at least one BFER comprises the first BFR comprises:
obtaining, by the first BFR, an ID of the at least one BFER according to the set identifier, the bit string, and the length of the bit string that are carried in the TLV;
checking, by the first BFR, whether an ID of the first BFR is comprised in the ID of the at least one BFER; and
in response to the ID of the first BFR being comprised in the ID of the at least one BFER, determining, by the first BFR, that the at least one BFER comprises the first BFR.

### Claim 23 (depends on 19)

The method according to claim 19, wherein the first BFR is a BFR on the link between the BFIR and the at least one BFER, and a packet header of the OAM request packet comprises a time-to-live (TTL); and
the determining, by the first BFR according to the OAM request packet, that a destination BFR corresponding to the OAM request packet is the first BFR comprises:
decreasing, by the first BFR, a value of the TTL by a preset value; and
determining, by the first BFR, that the value of the TTL obtained after the preset value is deducted reaches 0, and determining that the destination BFR corresponding to the OAM request packet is the first BFR.

### Claim 24 (depends on 23)

The method according to claim 23, wherein the method further comprises:
determining, by the first BFR, that the value of the TTL obtained after the preset value is deducted does not reach 0;
determining that the destination BFR corresponding to the OAM request packet is not the first BFR; and
sending, by the first BFR, the OAM request packet to the at least one BFER.

### Claim 25 (depends on 19)

The method according to claim 19, wherein the obtaining, by the first BFR, a first OAM response packet according to the ID of the BFIR comprises:
obtaining, according to the ID of the BFIR, the set identifier and the bit string corresponding to the BFIR;
obtaining a second OAM response packet according to the bit string corresponding to the BFIR, wherein a packet header of the second OAM response packet comprises the bit string corresponding to the BFIR and the ID of the first BFR, and a payload of the second OAM response packet comprises an OAM packet; and
obtaining the first OAM response packet by inserting a bit indexed explicit replication multiprotocol label switching label into the second OAM response packet according to the set identifier corresponding to the BFIR, wherein the BIER-MPLS label comprises a label corresponding to the set identifier corresponding to the BFIR.

### Claim 26 (depends on 25)

The method according to claim 25, wherein the obtaining, by the first BFR, a first OAM response packet according to the ID of the BFIR further comprises:
obtaining, by the first BFR, an ID of a second BFR, wherein the second BFR is a previous hop of the first BFR on the link between the BFIR and the at least one BFER; and
adding, by the first BFR, the ID of the second BFR into the payload of the second OAM response packet.