# US 9,438,511 B2 · Identifying a label-switched path (LSP) associated with a multi protocol label switching (MPLS) service and diagnosing a LSP related fault

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- Number: US 9,438,511 B2
- Document ID: US9438511B2
- Status: Granted
- Kind: B2
- Application number: 13/762,203
- Filed: 2013-02-07
- Published: 2014-06-12
- Granted: 2016-09-06
- Earliest claimed: 2012-12-11
- Assignees: Hewlett Packard Enterprise Development LP
- Applicants: Hewlett Packard Enterprise Development LP
- Inventors: Ullas Vasthare Veerappagowda; Akash Deep; Kotilingareddy Bhavanam; Muthukumar Suriyanarayanan; Kashinath Nallapeta Satyanarayana Setty; Chetna Bhagat
- Web page: https://patentgrep.com/patent/US9438511B2

## CPC

- H04L 45/507: {Label distribution}
- 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

Provided is a method of identifying a Label-switched Path (LSP) associated with a Multi Protocol Label Switching (MPLS) service in a network. An MPLS service is identified in a network and logical neighbors of the MPLS service are determined. For each logical neighbor of the MPLS service, an LSP label is identified. Based on the LSP label, a unique out segment of the LSP associated with the Multi Protocol Label Switching (MPLS) service is identified.

## Claims

### Claim 1

A method of identifying a Label-switched Path (LSP) associated with a Multi Protocol Label Switching (MPLS) service in a network, comprising:
by a processor:
identifying the MPLS service;
determining logical neighbors of the MPLS service;
for each logical neighbor of the MPLS service, identifying an LSP label
identifying a unique out segment of the LSP associated with the Multi Protocol Label Switching (MPLS) service based on the LSP label;
determining whether the LSP is a Traffic Engineering (TE) tunnel or determining whether the LSP is a Label Distribution Protocol (LDP) based path; and
storing the TE tunnel related information if the LSP is the TE tunnel or storing the LSP label related information if the LSP is the LDP based path; and
displaying the TE tunnel or displaying the LDP based path.

### Claim 2 (depends on 1)

The method of claim 1, further comprising determining an entire Label-switched Path (LSP) associated with the Multi Protocol Label Switching (MPLS) service upon identification of the unique out segment.

### Claim 3 (depends on 1)

The method of claim 1, further comprising:
determining whether the LSP is the Traffic Engineering (TE) tunnel; and
storing the TE tunnel related information if the LSP is the Traffic Engineering (TE) tunnel.

### Claim 4 (depends on 3)

The method of claim 3, further comprising displaying the TE tunnel.

### Claim 5 (depends on 2)

The method of claim 2, further comprising:
determining whether the LSP is the Label Distribution Protocol (LDP) based path; and
storing the LSP label related information if the LSP is the Label Distribution Protocol (LDP) based path.

### Claim 6 (depends on 5)

The method of claim 5, further comprising displaying the LDP based path.

### Claim 7

A method of diagnosing a Label-switched Path (LSP) related fault in a Multi Protocol Label Switching (MPLS) based network, comprising:
identifying all segments participating to form a Label-switched Path;
for each segment, determining an OutSegment Next Hop value on participating routers of the network;
polling each of said OutSegment Next Hop value to identify a modified OutSegment;
characterizing all Label-switched Paths related to the modified OutSegment as impacted;
characterizing Multi Protocol Label Switching (MPLS) services based on the impacted Label-switched Path as impacted; and
generating an incident to notify an impacted Multi Protocol Label Switching (MPLS) service.

### Claim 8 (depends on 7)

The method of claim 7, further comprising:
determining, for the modified OutSegment that exists, if there is a physical connectivity problem in a related label-switched patch; and
if present, characterizing the physical connectivity problem as a root cause for a reroute.

### Claim 9 (depends on 7)

The method of claim 7, further comprising characterizing a physical connectivity problem as a root cause for a Label-switched Path (LSP) down if an OutSegment does not exist.

### Claim 10

A system to identify a Label-switched Path (LSP) associated with a Multi Protocol Label Switching (MPLS) service in a network, comprising:
a processor;
a service mapping module, implemented by the processor to:
identify the MPLS service;
determine logical neighbors of the MPLS service;
for each logical neighbor of the MPLS service, identify an LSP label;
identify a unique out segment of the LSP associated with the Multi Protocol Label Switching (MPLS) service based on the LSP label;
determine whether the LSP is a Traffic Engineering (TE) tunnel or determine whether the LSP is a Label Distribution Protocol (LDP) based path; and
store the TE tunnel related information if the LSP is the TE tunnel or store the LSP label related information if the LSP is the LDP based path; and
a display device to display the Label-switched Path (LSP) associated with a Multi Protocol Label Switching (MPLS) service in a network.

### Claim 11 (depends on 10)

The system of claim 10, wherein the service mapping module determines an entire Label-switched Path (LSP) associated with the Multi Protocol Label Switching (MPLS) service upon identification of the unique out segment.

### Claim 12 (depends on 10)

The system of claim 10, wherein the MPLS service is one of a Layer 3 Virtual Private Network (VPN), Layer 2 VPN, Traffic Engineering (TE) tunnel and Internet Protocol television (IPTV).

### Claim 13 (depends on 10)

The system of claim 10, wherein the MPLS service is hosted on a network device.

### Claim 14 (depends on 13)

The system of claim 13, wherein the network device is a Provider Edge (PE) router.

### Claim 15 (depends on 10)

The system of claim 10, wherein the LSP is the Traffic Engineering (TE) tunnel.

### Claim 16 (depends on 10)

The system of claim 10, wherein the LSP is the Label Distribution Protocol (LDP) based path.

### Claim 17

A non-transitory processor readable medium, the non-transitory processor readable medium comprising machine executable instructions, the machine executable instructions when executed by a processor causes the processor to:
identify a Multi Protocol Label Switching (MPLS) service in a network; determine logical neighbors of the MPLS service;
for each logical neighbor of the MPLS service, identify an LSP label;
identify a unique out segment of Label-switched Path (LSP) associated with the Multi Protocol Label Switching (MPLS) service based on the LSP label;
determine an entire LSP for the MPLS service upon identification of the unique out segment;
identify all segments in the LSP for the MPLS service;
for each segment, determine an OutSegment Next Hop value on participating routers of the network;
poll each of the OutSegment Next Hop values to identify a modified OutSegment;
characterize all LSPs related to the modified OutSegment as impacted;
characterize MPLS services based on the impacted Label-switched Path as impacted; and
generate an incident to notify an impacted Multi Protocol Label Switching (MPLS) service.