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Perle Systems IOLAN CSS User Manual

Page 65

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User Commands 63

Configuring Users

framed-compression

Used for

User Service

PPP

or

SLIP

, determines whether Van Jacobsen Compression is

used on the link. VJ compression is a means of reducing the standard TCP/IP header
from 40 octets to approximately 5 octets. This gives a significant performance
improvement, particularly when interactive applications are being used. For example,
when the user is typing, a single character can be passed over the link with a packet as
small as 5 octets as opposed to 40 octets when no JV compression is used. VJ
Compression has little effect on other types of links, such as ftp, where the packets are
much larger. The

Framed Compression

value will be used in preference to the

VJ

Compression

value set for a

Line

. The default is

Off

.

framed-ip

Used for

User Service PPP

or

SLIP

, sets the IP address of the remote user. Enter the

address in dot decimal notation as follows:

z

255.255.255.254

(default)—The IOLAN will use the

Remote IP Address

set in

the

PPP

settings for the line.

z

255.255.255.255

—When the

User Service

is

PPP

, the IOLAN will allow the

remote machine to specify its IP address (overriding the Remote IP Address
configured in the line,

PPP

settings). When the

User Service

is

SLIP

, the IOLAN

will use the

Remote IP Address

set for the line (no negotiation).

z

n.n.n.n

—(where

n

is a number) Enter the IP address of your choice. This IP

address will then be used in preference to the

Remote IP Address

set for a line.

framed-interface-id

Used for

User Service PPP

, sets the IPv6 address of the remote user.

framed-mtu

Used for

User Service

PPP

or

SLIP

, specifies the maximum size of packets, in bytes,

being transferred across the link. On noisy links it might be preferable to fragment large
packets being transferred over the link, since there will be quicker recovery from errors.
Depending on whether you have selected a

User Service

of

SLIP

or

PPP

, details are as

follows:

z

PPP

Framed MTU

will be the maximum size of packets that the IOLAN port will

accept. This value is negotiated between the two ends of the link. The valid range is
64-1500. The default value is

1500

bytes.

z

SLIP

Framed MTU

will be the maximum size of packets being sent by the

IOLAN. The IOLAN will send SLIP packets in the range 256-1500 bytes. The
default value is

256

bytes.

The

Framed MTU

value will be used in preference to the

MTU

/

MRU

values set for a

Line

.