Contents
Main
Download NMIS8
Opmantek.com
NMIS
randomKaos
Books
Network Management
Web Design
Internet Protocol
Reference Info
Networking
Internet Reference
Consultants
Unix Stuff
HTML Reference
Seven Deadly SINS
Google

sins.com.au
Web
 
 
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Contents
Main
Download NMIS8
Opmantek.com
NMIS
randomKaos
Books
Network Management
Web Design
Internet Protocol
Reference Info
Networking
Internet Reference
Consultants
Unix Stuff
HTML Reference
Seven Deadly SINS
Google

sins.com.au
Web
 
 
Valid XHTML 1.0 Transitional
If device A is sending data to device B accross a Frame Relay intrastructure and one of the intermediate Frame Relay switches encounters congestion, congestion being full buffers, over subscribed port, overloaded resources, etc, it will set the BECN bit on packets being returned to the sending device and the FECN bit on the packets being sent to the receiving device.  This has the effect of telling the sending router to Back off and apply flow control like traffic Shaping and informs the receiving device that the flow is congested and that it should inform upper layer protocols, if possible, that it should close down windowing etc to inform the sending application to slow down.

A FECN tells the receiving device that the path is congested so that the upper layer protocols should expect some delay. The BECN tells the transmitting device that the Frame Relay network is congested and that it should "back off" to allow better throughput.

FECN (Forward Error Congestion Notification)

BECN (Backward Error Congestion Notification)

NMIS from Opmantek includes full support for FECN and BECN collection and reporting for free.