US5317565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of sequencing bus operations in a simplex switch
Assignee: International Business Machines Corp
•
Filing: 1993-01-26
•
Granted: 1994-05-31
•
Expires: 2013-01-26
Abstract
Abstract A sequencing scheme is provided for prioritizing bus operations occurring in simplex switches which interconnect subsystems in a data communications system, thereby yielding improved aggregate system data throughput. The sequencing scheme provides procedures which simultaneously accommodate (i) concurrently pending requests to a first control bus which processes only circuit switched operations and (ii) concurrently pending requests to a second control bus which processes only packet switched operations, in an order which optimizes link level control message throughput of the simplex switch. The control messages which are coordinated by the sequencing scheme include connect and disconnect requests, connect and disconnect request acknowledgments, and data acknowledgments. All connect request and disconnect requests are managed by a connection processing (CP) bus, which operates as a circuit switching bus, and all data acknowledgments and connect request acknowledgments from subsystems attached to a cascaded switch are made over an out-of-band (OB) bus, which operates as a packet switching bus. Because connect and disconnect operations over the CP bus can proceed independently of acknowledgment operations over the OB bus, the sequencing procedures for each of the control buses are permitted to operate independently and simultaneously.
Inventors
- 👤 Richard S. Crouse
- 👤 John J. Cazzolla
- 👤 Luke L. Chang
- 👤 Marco M. Hurtado
- 👤 Kha D. Nguyen
- 👤 Jose L. Rivero
- 👤 Jose J. Ruiz
- 👤 Louis Salcedo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:55
CPC Classifications
H; H04; H04L; H04L49/00; H04L49/10; H04L49/104; H04L49/105; H04L49/107; H04L12/00; H04L12/50; H04L49/101; H04L49/106; H04L49/25; H04L49/253; H04L49/255; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04J; H04J2203/00; H04J2203/0001; H04J2203/0003; H04J2203/0005; H04L12/28; H04L12/44; H04L2012/445; H04L49/20; H04L49/205; H04L49/35; H04L49/351
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
147 words
A prioritization scheme for determining a predefined sequential order of processing each contending connection and disconnection request through a simplex switch which is initiated by interconnected subsystems in a data communications system, independent of the order in which said requests are initiated, said prioritization scheme comprising the steps of: (i) determining which of said contending requests are disconnect requests and processing all disconnect requests before processing any connect requests; (ii) for each contending group of disconnect requests, determining a first subset of disconnect requests which are destined for an interconnected subsystem which currently has pending against it a connection request and processing said first subset of requests before processing a second subset of disconnect requests which are destined for interconnected subsystems which currently have no connection requests pending against them; and then (iii) for each contending group of connect requests, processing non-queued requests before processing queued requests.
Claim 2
Dependent Claim
147 words
A prioritization scheme for determining a predefined sequential order of processing each contending connection and disconnection request through a simplex switch which is initiated by interconnected subsystems in a data communications system, independent of the order in which said requests are initiated, said prioritization scheme comprising the steps of: (i) determining which of said contending requests are disconnect requests and processing all disconnect requests before processing any connect requests; (ii) for each contending group of disconnect requests, determining a first subset of disconnect requests which are destined for an interconnected subsystem which currently has pending against it a connection request and processing said first subset of requests before processing a second subset of disconnect requests which are destined for interconnected subsystems which currently have no connection requests pending against them; and then (iii) for each contending group of connect requests, processing non-queued requests before processing queued requests.
Claim 3
Dependent Claim
215 words
A prioritization scheme for determining the order of processing contending connection and disconnection requests through a simplex switch which are initiated by interconnected subsystems in a data communications system, said data communications system comprises of at least two cascaded simplex switches each having connected thereto at least one interconnected subsystem, said prioritization scheme comprising the steps of: (i) determining which of said contending requests are disconnect requests and processing all disconnect requests before processing any connect requests; (ii) for each contending group of disconnect and connect requests, determining a first subset of requests which are destined for an interconnected subsystem which currently has pending against it a connection request and processing said first subset of requests before processing a second subset of requests which are destined for interconnected subsystems which currently have no connection requests pending against them; and determining, for each of said first and second subsets of requests, cascaded requests which are requests destined for an interconnected subsystem that is not attached to the same simplex switch as the subsystem originating the request but is instead attached to a cascaded simplex switch, and processing said cascaded requests before processing non-cascaded requests which are requests destined for an interconnected subsystem that is attached to the same simplex switch as the subsystem originating the request.
Claim 4
Dependent Claim
215 words
A prioritization scheme for determining the order of processing contending connection and disconnection requests through a simplex switch which are initiated by interconnected subsystems in a data communications system, said data communications system comprises of at least two cascaded simplex switches each having connected thereto at least one interconnected subsystem, said prioritization scheme comprising the steps of: (i) determining which of said contending requests are disconnect requests and processing all disconnect requests before processing any connect requests; (ii) for each contending group of disconnect and connect requests, determining a first subset of requests which are destined for an interconnected subsystem which currently has pending against it a connection request and processing said first subset of requests before processing a second subset of requests which are destined for interconnected subsystems which currently have no connection requests pending against them; and determining, for each of said first and second subsets of requests, cascaded requests which are requests destined for an interconnected subsystem that is not attached to the same simplex switch as the subsystem originating the request but is instead attached to a cascaded simplex switch, and processing said cascaded requests before processing non-cascaded requests which are requests destined for an interconnected subsystem that is attached to the same simplex switch as the subsystem originating the request.
Claim 5
Dependent Claim
53 words
The method of claim 2, wherein said connection and disconnection requests are passed through to said cascaded simplex switches via a plurality of I/O ports on each of said switches, each of said I/O ports being adapted to be connected to either an attached subsystem or an I/O port on another simplex switch.
Claim 6
Dependent Claim
44 words
The method of claim 3, wherein said connection and disconnection requests are passed through to said cascaded simplex switches via sixteen I/O ports on each of said switches, said sixteen I/O ports provided by eight port modules each having a pair of I/O ports.
Claim 7
Dependent Claim
25 words
The method of claim 3, further comprising the step of queuing requests in a buffer in each of said I/O ports on said simplex switches.
Claim 8
Dependent Claim
38 words
The method of claim 5, further comprising the step of passing incoming and outgoing data, respectively, over dedicated data input buses and dedicated data output buses which connect each of said I/O ports to an internal switching fabric.
Claim 9
Dependent Claim
18 words
The method of claim 2, wherein said connect and disconnect requests are managed by a circuit switching bus.
Claim 10
Dependent Claim
167 words
A prioritization scheme for determining the order of processing contending data acknowledgment and connect request acknowledgment messages through a simplex switch which are initiated by interconnected subsystems in a data communications system, said data communications system being comprised of at least two cascaded simplex switches each having connected thereto at least one interconnected subsystem, said prioritization scheme comprising the steps of: (i) determining which of said contending messages are connect request acknowledgement messages and processing all connect request acknowledgement messages before processing any data acknowledgment messages; and (ii) determining, for each contending group of connect request acknowledgement messages and data acknowledgment messages, cascaded messages which are messages destined for an interconnected subsystem that is not attached to the same simplex switch as the subsystem originating the message but is instead attached to a cascaded simplex switch, and processing said cascaded messages before processing non-cascaded messages which are messages destined for an interconnected subsystem that is attached to the same simplex switch as the subsystem originating the message.
Claim 11
Dependent Claim
167 words
A prioritization scheme for determining the order of processing contending data acknowledgment and connect request acknowledgment messages through a simplex switch which are initiated by interconnected subsystems in a data communications system, said data communications system being comprised of at least two cascaded simplex switches each having connected thereto at least one interconnected subsystem, said prioritization scheme comprising the steps of: (i) determining which of said contending messages are connect request acknowledgement messages and processing all connect request acknowledgement messages before processing any data acknowledgment messages; and (ii) determining, for each contending group of connect request acknowledgement messages and data acknowledgment messages, cascaded messages which are messages destined for an interconnected subsystem that is not attached to the same simplex switch as the subsystem originating the message but is instead attached to a cascaded simplex switch, and processing said cascaded messages before processing non-cascaded messages which are messages destined for an interconnected subsystem that is attached to the same simplex switch as the subsystem originating the message.
Claim 12
Dependent Claim
53 words
The method of claim 8, wherein said connection and disconnection requests are passed through to said cascaded simplex switches via a plurality of I/O ports on each of said switches, each of said I/O ports being adapted to be connected to either an attached subsystem or an I/O port on another simplex switch.
Claim 13
Dependent Claim
44 words
The method of claim 9, wherein said connection and disconnection requests are passed through to said cascaded simplex switches via sixteen I/O ports on each of said switches, said sixteen I/O ports provided by eight port modules each having a pair of I/O ports.
Claim 14
Dependent Claim
25 words
The method of claim 9, further comprising the step of queuing requests in a buffer in each of said I/O ports on said simplex switches.
Claim 15
Dependent Claim
38 words
The method of claim 11, further comprising the step of passing incoming and outgoing data, respectively, over dedicated data input buses and dedicated data output buses which connect each of said I/O ports to an internal switching fabric.
Claim 16
Dependent Claim
21 words
The method of claim 8, wherein said data acknowledgment and connect request acknowledgment messages are managed by a packet switching bus.
References Cited (Backward Citations)
US4009344A
Cited
US4307461A
Cited
US4328543A
Cited
US4706081A
Cited
US4654845A
Cited
US4713806A
Cited
US4748658A
Cited
US4817082A
Cited
US4943959A
Cited
US4972368A
Cited
US5051985A
Cited
US5042031A
Cited
US5070501A
Cited
US5119366A
Cited
US5144293A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-30 | 1997-11-29 | 1998-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-30 | 2001-11-29 | 2002-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-30 | 2005-11-29 | 2006-05-31 | $7700.00 | Window Closed / Lapsed |