Cabletron Systems Cabletron CyberSWITCH CSX5500, Руководство пользователя

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Central Site Remote Access Switch 411
C
ONFIGURING
O
THER
A
DVANCED
O
PTIONS
Compression Options
C
OMPRESSION
O
PTIONS
C
ONFIGURATION
E
LEMENTS
C
OMPRESSION
S
UBSYSTEM
S
TATUS
You may enable or disable the compression subsystem status. This option provides enable/disable
control over the entire compression subsystem within the system. If this option is enabled, the
system will negotiate compression with remote devices per their individual
device compression
configuration . If this option is disabled, the system will not negotiate compression with any remote
device. The default value is enabled.
Note that enable/disable applies to all protocols which support compression.
D
EFAULT
P
ER
-D
EVICE
C
OMPRESSION
S
ETTING
You may enable or disable the per-device compression setting. This is in addition to the global
compression enable/disable state described above. The Default Per-Device Compression setting
defines the initial value for the per-device state when you add a new device to the on-node device
table. Or, if the device is authenticated via an off node server, the device will be given its
compression enable/disable state based on this value when no value is delivered by the off-node
database.
You may later change a specific device’s enable/disable state.
The per-device compression enable/disable state is only supported for connections using the PPP
protocol. The default value is enabled.
S
TARTING
PPP STAC-LZS S
EQUENCE
N
UMBER
Default value is 1. When using PPP Compression with the STAC-LZS protocol, a sequence
numbering scheme can be used whose initial value is required to be 1 by the protocol specification.
Some devices from other vendors do not start with 1. This results in a resynchronization sequence
on the first frame which is exchanged. When the user device fully supports the CCP protocol’s
Reset mechanism, this will only result in the minor inconvenience of a lost frame at the beginning
of a session. However, if such a device’s resynchronization mechanism is to completely renegotiate
CCP, this sequence will repeat infinitely.
This option provides an escape mechanism to allow interworking with such devices by modifying
the initial PPP STAC sequence number.
The Starting PPP STAC Sequence Number is maintained for each device. The value which appears
on this configuration screen provides the default value for the per-device value. When you add a
new device to the on-node device table, that device’s starting sequence number option will be
assigned the value which appears on this screen. You can then change this for each individual
device. Or, if the device is authenticated via an off node server that does not deliver a value for this
configuration item, the device will be given its starting sequence number from the value on this
menu
As its name implies, this option only applies to connections which utilize the PPP protocol with
STAC-LZS compression and sequence numbers checking.