US5878031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loopback mechanism for frame relay OAM
Assignee: RPX Clearinghouse LLC
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Filing: 1997-11-18
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Granted: 1999-03-02
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Expires: 2017-11-18
Abstract
Abstract A loopback mechanism uses frame relay OAM loopback frames which eliminate the need for location identifiers and reduces overhead and complexity. The frames replace source and destination loopback location identifiers by a loopback indicator field, a send node count field and a return node count field. The originating node of the loopback procedure sets the number of intermediate frame relay nodes to be traversed. The intermediate frame relay nodes simply increment or decrement the node count, depending on the direction of the loopback frame.
Inventors
- 👤 Khalid Ahmad
- 👤 Jan Medved
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:35
CPC Classifications
H; H04; H04L; H04L43/00; H04L43/50; H04L12/00; H04L12/54; H04L12/56; H04L12/5601; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04L2012/5625; H04L2012/5628; H04L2012/5638; H04L2012/5646; H04L2012/5652
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
124 words
A method of performing a loopback function in a telecommunications network which carries frame relay services, comprising steps of: sending from a source node an OAM frame towards a loopback node, the OAM frame having a correlation tag field set to a preset value, a loopback indicator field set to sending, a send node count field set to the number of intermediate nodes and a return node count field set to a predetermined value; receiving the OAM frame which has been looped back; and extracting the received OAM frame, on the condition that the preset value of the correlation tag field is valid, the loopback indicator field is set to returning and the value of the return node count field meets a certain criterion.
Claim 2
Independent Claim
124 words
A method of performing a loopback function in a telecommunications network which carries frame relay services, comprising steps of: sending from a source node an OAM frame towards a loopback node, the OAM frame having a correlation tag field set to a preset value, a loopback indicator field set to sending, a send node count field set to the number of intermediate nodes and a return node count field set to a predetermined value; receiving the OAM frame which has been looped back; and extracting the received OAM frame, on the condition that the preset value of the correlation tag field is valid, the loopback indicator field is set to returning and the value of the return node count field meets a certain criterion.
Claim 3
Dependent Claim
57 words
The method according to claim 1, further comprising steps of at intermediate frame relay nodes, incrementing the return node count field when the loopback indicator field is set to sending and decrementing at intermediate frame relay nodes the return node count field when the loopback indicator field is set to returning; and forwarding the OAM frame downstream.
Claim 4
Dependent Claim
39 words
The method according to claim 2 wherein the return node count field is set to 0 at the source node and the certain criterion is that the return node count field of the received OAM frame is also 0.
Claim 5
Dependent Claim
42 words
The method according to claim 1, further comprising a step of the source node sending an initialization OAM frame towards the loopback node, the initialization OAM frame having the send node count field set to a predetermined value indicating an initialization procedure.
Claim 6
Dependent Claim
36 words
The method according to claim 4 wherein the OAM initialization frame has its loopback indicator field set to sending, its send node count field set to 0 and its return node count field set to 0.
Claim 7
Dependent Claim
46 words
The method according to claim 1, further comprising steps of: the source node sending an end-to-end loopback frame, the end-to-end loopback frame having the send node count field set to a particular value; and receiving the end-to-end loopback frame whose loopback indicator field set to loopback.
Claim 8
Dependent Claim
21 words
The method according to claim 6 wherein the end-to-end loopback frame has its send node count field set to all ones.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-01 | 2002-08-31 | 2003-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-01 | 2006-08-31 | 2007-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-01 | 2010-08-31 | 2011-03-02 | $7700.00 | Window Closed / Lapsed |