Avaya Configuring DLSw Services User Manual download pdf (Page 67)

DLSw Implementation Notes

303523-A Rev. 00

2-11

TCP Considerations

TCP timers allow you to configure DLSw to periodically give TCP data to

transmit if a connection is inactive for a period of time. The mechanism by which

TCP determines a lost connection (either a failed link with no rerouting possible,

or the remote router is unavailable) is based on TCP attempts to deliver this data.

If TCP does not receive an acknowledgment after a series of retries, it declares the

connection down and informs DLSw. DLSw then manages the currently active

sessions.

There are four main configuration parameters associated with TCP timers:

• KeepAlive Time

• KeepAlive Retry Timer

• KeepAlive Retries

• TCP Inact Time

For information about the parameters, refer to Chapter 3

Flow Control

DLSw uses the following three flow control mechanisms to provide reliable

end-to-end delivery of packets:

• LLC2 flow control

• TCP flow control

• DLSw RFC 1434 fixed and RFC 1795 adaptive pacing

TCP and LLC2 continue to assert flow control until congestion clears on a given

TCP connection.

The default settings for system parameters relevant to LLC2 and TCP flow control

are suitable for the majority of your DLSw service requirements.

LLC2 Flow Control

The LLC2 protocol interface provides a bidirectional window and a SAP credit

allocation, that together manage flow control on individual LLC2 connections

between the router and LAN-attached SNA or NetBIOS systems.

1 2 ... 62 63 64 65 66 67 68 69 70 71 72 ... 291 292

No comments

Avaya Configuring DLSw Services User Manual Page 67