Immediate ready implementation of virtually congestion free guaranteed service capable network: external internet nextgentcp (square waveform) TCP friendly san

• US 20080037420A1
• Filed: 05/25/2007
• Published: 02/14/2008
• Est. Priority Date: 10/08/2003
• Status: Abandoned Application

• Current Assignee: Bob Tang
• Original Assignee: Bob Tang
• Inventors: Tang, Bob
• Application Number:
  US11/807,265
• Publication Number:
  US 20080037420A1
• Time in Patent Office: Days
• US Class Current: 370/229
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/187 Details of sliding window management
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures

Abstract

Various techniques of simple modifications to TCP/IP protocol and other susceptible protocols and related network'"'"'s switches/routers configurations, are presented for immediate ready implementations over external Internet of virtually congestion free guaranteed service capable network, without requiring use of existing QoS/MPLS techniques nor requiring any of the switches/routers softwares within the network to be modified or contribute to achieving the end-to-end performance results nor requiring provision of unlimited bandwidths at each and every inter-node links within the network.

Claims

1. Methods for improving TCP and/or TCP like protocols and/or other protocols, which could be capable of completely implemented directly via TCP/Protocol stack software modifications without requiring any other changes/re-configurations of any other network components whatsoever and which could enable immediate ready guaranteed service PSTN transmissions quality capable networks and without a single packet ever gets congestion dropped, said methods avoid and/or prevent and/or recover from network congestions via complete or partial ‘

pause’

/‘

halt’

in sender'"'"'s data transmissions when congestion events are detected such as congestion packet drops and/or returning ACK'"'"'s round trip time RTT/one way trip time OTT comes close to or exceeded certain threshold value eg known value of the flow path'"'"'s uncongested RTT/OTT or their latest available best estimate min(RTT)/min(OTT).

2. Methods for improving TCP and/or TCP like protocols and/or other protocols, which could be capable of completely implemented directly via TCP/Protocol stack software modifications without requiring any other changes/re-configurations of any other network components whatsoever and which could enable immediate ready guaranteed service PSTN transmissions quality capable networks and without a single packet ever gets congestion dropped, said methods comprises any combinations/subsets of (a) to (c):

(a) makes good use of new realization/technique that TCP'"'"'s Sliding Window mechanism'"'"'s ‘

Effective Window’ and

/or Congestion Window CWND needs not be reduced in size to avoid and/or prevent and/or recover from congestions;

(b) Congestions instead are avoided and/or prevented and/or recovered from via complete or partial ‘

pause’

/‘

halt’

in sender'"'"'s data transmissions when congestion events are detected such as congestion packet drops and/or returning ACK'"'"'s round trip time RTT/one way trip time OTT comes close to or exceeded certain threshold value eg known value of the flow path'"'"'s uncongested RTT/OTT or their latest available best estimate min(RTT)/min(OTT);

(c) Instead or in place or in combination with (b) above, TCP'"'"'s Sliding Window mechanism'"'"'s ‘

Effective Window’ and

/or Congestion Window CWND value is reduced to a value algorithmically derived dependent at least in part on latest returned round trip time RTT/one way trip time OTT value when congestion is detected, and/or the particular flow path'"'"'s known uncongested round trip time RTT/one way trip time OTT or their latest available best estimate min(RTT)/min(OTT), and/or the particular flow path'"'"'s latest

observed longest round trip time max(RTT)/one way trip time max(OTT).

3. Methods for virtually congestion free guaranteed service capable data communications network/Internet/Internet subsets/Proprietary Internet segment/WAN/LAN [hereinafter refers to as network] with any combinations/subsets of features (a) to (f):

(a) where all packets/data units sent from a source within the network arriving at a destination within the network all arrive without a single packet being dropped due to network congestions;

(b) applies only to all packets/data units requiring guaranteed service capability;

(c) where the packet/data unit traffics are intercepted and processed before being forwarded onwards;

(d) where the sending source/sources traffics are intercepted processed and forwarded onwards, and/or the packet/data unit traffics are only intercepted processed and forwarded onwards at the originating sending source/sources;

(e) where the existing TCP/IP stack at sending source and/or receiving destination is/are modified to achieve the same end-to-end performance results between any source-destination nodes pair within the network, without requiring use of existing QoS/MPLS techniques nor requiring any of the switches/routers softwares within the network to be modified or contribute to achieving the end-to-end performance results nor requiring provision of unlimited bandwidths at each and every inter-node links within the network; and

(f) in which traffics in said network comprises mostly of TCP traffics, and other traffics types such as UDP/ICMP . . . etc do not exceed, or the applications generating other traffics types are arranged not to exceed, the whole available bandwidth of any of the inter-node link/s within the network at any time, where if other traffics types such as UDP/ICMP. do exceed the whole available bandwidth of any of the inter-node link/s within the network at any time only the source-destination nodes pair traffics traversing the thus affected inter-node link/s within the network would not necessarily be virtually congestion free guaranteed service capable during this time and/or all packets/data units sent from a source within the network arriving at a destination within the network would not necessarily all arrive ie packet/s do gets dropped due to network congestions.

4. Methods in accordance with claim 3, wherein in said methods the improvements/modifications of protocols is effected at the sender TCP.

5. Methods in accordance with claim 3, wherein in said methods the improvements/modifications of protocols is effected at the receiver side TCP.

6. Methods in accordance with claim 3 above, wherein in said methods the improvements/modifications of protocols is effected in the network'"'"'s switches/routers nodes.

7. Methods wherein the improvements/modifications of protocols is effected in any combinations of locations as specified in claim 6.

8. Methods wherein the improvements/modifications of protocols is effected in any combinations of locations as specified in claim 6, wherein said methods the existing ‘

Random Early Detect’

RED and/or ‘

Explicit Congestion Notification’

ECN are modified/adapted to give effect to that disclosed in claim 7 above.

9. Methods in accordance with claim 8 above or independently, wherein the switches/routers in the network are adjusted in their configurations or setups or operations, such as eg buffer size adjustments, to give effect to that disclosed above.

10. Methods in accordance with claim 9, wherein said methods:

existing protocols RFCs are modified such that sender'"'"'s CWND value is instead now never reduced/decremented whatsoever, except to temporarily effect ‘

pause’

/‘

halt’

of sender'"'"'s data transmissions upon congestions detected (eg by temporarily setting sender'"'"'s CWND=1*MSS during ‘

pause’

/‘

halt’ and

after ‘

pause’

/‘

halt’

completed to then restore sender'"'"'s CWND value to eg existing CWND value prior to ‘

pause’

/halt or to some algorithmically derived value the ‘

pause’

/halt’

interval could be set to eg arbitrary 300 ms or algorithmically derived such as Minimum (latest RTT of returning ACK packet triggering the 3^rd DUP ACK fast retransmit OR latest RTT of returning ACK packet when RTO Timedout, 300 ms) or algorithmically derived such as Minimum (latest RTT of returning ACK packet triggering the 3^rd DUP ACK fast retransmit OR latest RTT of returning ACK packet when RTO Timedout, 300 ms, max(RTT))

AND/OR

existing protocols RFCs are modified such that SSThresh is instead now set to existing CWND value prior to the congestion detection which triggers ‘

pause’

/‘

halt’

, ie subsequent CWND increments would only be linear additive beyond CWND value.

11. Methods as in accordance with claim 10, wherein in said methods if the congestion detection is due to non-congestion drops eg physical transmission errors or BER ie not due to congestion packet drops, then the ‘

pause’

/‘

halt’

count down interval will be set to ‘

0’

instead, ie no actual ‘

pause’

/‘

halt’

of data transmissions will be initiated, also note that any pre-existing current ‘

pause’

/‘

halt’

in progress will be allowed to progress normally onto counted down;

congestion detection could be attributable to non-congestion reasons if eg latest returned ACK'"'"'s RTT when 3^rd DUP ACK triggering fast retransmit or latest returned ACK'"'"'s RTT when RTO Timedout−

min(RTT)<

eg 200 ms.

12. Methods as in accordance with claim 11, wherein in said methods if there is already a current ‘

pause’

/‘

halt’

in progress, a subsequent ‘

real’

congestion event indication will now extends the current ‘

pause’

/‘

halt’

interval, a matter of merely setting/overwriting the present ‘

pause’

/‘

halt’

countdown to a new value such as eg Minimum (latest RTT of returning ACK packet triggering the 3^rd DUP ACK fast retransmit OR latest RTT of returning ACK packet when RTO Timedout, 300 ms, max(RTT)).

13. Methods as in accordance with claim 12, wherein said methods:

any one, or all or almost all routers and switches at a node in the network to be modified/software upgraded to immediately generate total of 3 DUP ACKs to the traversing flows'"'"' sources to indicate to the sources to reduce their transmit rates when the node starts to buffer the traversing TCP flows'"'"' packets (ie forwarding link now is 100% utilised and the aggregate traversing TCP flows'"'"' sources'"'"' packets start to be buffered);

the 3 DUP ACKs generation may alternatively be instead triggered eg when the forwarding link reaches a specified utilisation level eg 95% 98% . . . etc, or some other trigger conditions specified

14. Methods as in accordance with claim 13, wherein in said methods:

existing RED and ECN could similarly have their algorithm modified as outlined in the principles and schemes contained in any of the claims above, enabling real time guaranteed service capable networks (or non congestion drops, and/or much much less buffer delays networks).