blank.gif (43 bytes)

Church Of The
Swimming Elephant

Flow Control Connected: An Internet Encyclopedia
Flow Control

Up: Connected: An Internet Encyclopedia
Up: Programmed Instruction Course
Up: Section 4 - The TCP Protocol
Prev: TCP Protocol Overview
Next: Sliding Window

Flow Control

Flow Control TCP manages limited network bandwidth by performing flow control.

Modern data networks are designed to support a diverse range of hosts and communication mediums. Consider a 200MHz Pentium-based host transmitting data to a 25MHz 80386/SX. Obviously, the Pentium will be able to drown the slower processor with data. Likewise, consider two hosts, each using an Ethernet LAN, but with the two Ethernets connected by a 28.8 Kbps modem link. If one host begins transmitting to the other at Ethernet speeds, the modem link will quickly become overwhelmed. In both cases, flow control is needed to pace the data transfer at an acceptable speed.

Request/reply flow control requires each data packet to be acknowledge by the remote host before the next packet is sent. Sliding window algorithms, used by TCP, permit multiple data packets to be in simultaneous transit, making more efficient use of network bandwidth. Finally, Internet's Unreliable Delivery Model allows packets to be discarded if network resources are not available, and demands that protocols make provisions for retransmission.

Next: Sliding Window

Connected: An Internet Encyclopedia
Flow Control


Protect yourself from cyberstalkers, identity thieves, and those who would snoop on you.
Stop spam from invading your inbox without losing the mail you want. We give you more control over your e-mail than any other service.
Block popups, ads, and malicious scripts while you surf the net through our anonymous proxies.
Participate in Usenet, host your web files, easily send anonymous messages, and more, much more.
All private, all encrypted, all secure, all in an easy to use service, and all for only $5.95 a month!

Service Details

Have you gone to church today?
All pages ©1999, 2000, 2001, 2002, 2003 Church of the Swimming Elephant unless otherwise stated
Church of the Swimming Elephant©1999, 2000, 2001, 2002, 2003 is a wholly owned subsidiary of Packetderm, LLC.

Packetderm, LLC
210 Park Ave #308
Worcester, MA 01609