User's Guide for MS-DOS Clients

349

Using Remote Access Service

Tuning

This section includes modiﬁcations you can make that will increase the

performance of RAS. You can tune RAS performance on your system by

modifying LANMAN.INI parameters.

Modifying LANMAN.INI on MS-DOS-based Workstations

On a LAN Manager Enhanced workstation, RAS modiﬁes the

wrkheuristics entry of the [workstations] section for optimal performance

over a telephone line. The modiﬁed wrkheuristics entry reads as follows:

wrkheuristics = xxxxxxxx00x6xx1xxxxxxxxxxxxxxxxxx

These settings are optimized for RAS. They are different from those for

LAN Manager networks without RAS.

NOTE: If you use your workstation as a LAN workstation as well as a RAS workstation, the

RAS optimization of wrkheuristics will cause the computer to operate at less than

optimal levels when used as a LAN workstation. Performance on the LAN will be

acceptable. The following wrkheuristics settings are changed:

The reasons for these settings are as follows:

• If oplock is turned on, the remote client's redirector opens files in exclusive mode

and turns on the write behind, read ahead feature. If this feature is turned on and

the telephone line is disconnected, data is lost. The telephone line may be discon-

nected by the user or by some hardware problem.

• If open and read is turned on, as soon as a user opens a file, the redirector reads

data from that file before the user explicitly requests it to do so. This operation

yields better system response on the LAN, but on an asynchronous line it unnec-

essarily retards performance in cases where the user does not want to read data

Position Value

Meaning

8 0 Do not request oplock (opportunistic locking).

9 0 Do not use open and read.

14 1 Do not use raw read/write server message blocks.