Browse Prior Art Database

Improving Packet Communications Bandwith

IP.com Disclosure Number: IPCOM000123415D
Original Publication Date: 1998-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 94K

Publishing Venue

IBM

Related People

Fisk, BP: AUTHOR [+4]

Abstract

Packet communications typically uses handshaking techniques to move data packets safely from sender to receiver. Specifically messages are broken down into packets and each packet sent is acknowledged by sending an ack from receiver to sender. The transmitter starts a timer as it sends the packet. If an ack is not received in some specified time, the data packet is assumed to have been lost. If transmission was successful the receiver sends a positive ack to the sender, and if the receiver detects a problem it returns a negative ack. If the transmitter receives a negative ack, or the timer indicates a lost packet, the sender retransmits the data packet.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Improving Packet Communications Bandwith

   Packet communications typically uses handshaking techniques
to move data packets safely from sender to receiver.  Specifically
messages are broken down into packets and each packet sent is
acknowledged by sending an ack from receiver to sender.  The
transmitter starts a timer as it sends the packet.  If an ack is not
received in some specified time, the data packet is assumed to have
been lost.  If transmission was successful the receiver sends a
positive ack to the sender, and if the receiver detects a problem it
returns a negative ack.  If the transmitter receives a negative ack,
or the timer indicates a lost packet, the sender retransmits the data
packet.

   The efficiency of this protocol can be improved by
organizing the data packets in bunches.  However the bunch approach
suffers from the delay associated with handshaking following the end
of a bunch of messages.  The problem is that messages may be small
(tens of bytes) or very large (Gigabytes) and sending a batch of
messages gives no indication of the data size to be sent.

   The approach described here moves data independently of
message size and boundaries.  The design of the message-moving
program is split into two layered components at both sender and
receiver.  The higher (data) layer deals in application messages and
the lower (packet) layer deals in packets (irrespective of message
boundaries).  In the case where the transmission of bunches is
supported then the following scheme applies:
  At the sender the data layer is responsible for decomposing
  the message into packet sized pieces and passing the packets
  to the packet layer.  The packet layer component at the
  sender sends bunches of n packets to the packet layer of the
  receiver, sequentially one packet at a time.  Finally the
  receiver packet layer component passes the packets to the
  data layer at the receiver which constitutes the messages.
  An acknowledgement scheme, which informs the sender of the
  successful receipt of packets by the sender, is implemented
  around bunches of packets.

   Where bunches are not supported, then the scheme is:
  At the sender the data layer is responsible for decomposing
  the message into packet sized pieces and passing the packet...