Additional Remote Networking
Bandwidth On Demand
5-5
By default, sites will only attempt to bring up one port to a remote site in a LAN to LAN connection. If the
amount of incoming data on the Ethernet exceeds the current bandwidth of the serial port (and the SCS is
configured not to dial up additional bandwidth), congestion occurs and the extra data is discarded.
To avoid congestion, the SCS enables you to customize a site’s use of bandwidth. As it is needed, additional
bandwidth will be added. The SCS will assign more ports to the site until it has enough bandwidth or reaches
a certain threshold. When it is no longer needed, the extra bandwidth will be removed.
5.3.1 How Bandwidth is Controlled
A site’s use of bandwidth is controlled by the following factors:
The initial and maximum bandwidth allotted to the site. These are static values.
The threshold at which additional bandwidth should be added. This threshold is a percentage of the
currently-dialed bandwidth.
The threshold at which unnecessary (unused) bandwidth should be removed. This threshold is a
percentage of the currently-dialed bandwidth.
The period of time during which the current bandwidth usage is measured.
The delay between bandwidth adjustments.
By default, additional bandwidth will not be added to a connection. In order for a connection to have flexible
bandwidth (bandwidth that is added and removed as necessary), the site’s maximum bandwidth must be
configured, as well as the thresholds at which bandwidth is added and removed.
Note:
The initial bandwidth allotted to the site may also be configured. This is optional.
The threshold at which bandwidth is added and removed should have some room between them to regulate
how often bandwidth is added and removed. The “add bandwidth” threshold should be set to a percentage
between 80 and 100 percent; the “remove bandwidth” threshold should generally be set to less than 50%. If
the threshold values are set too close to one another, the connections will
thrash
; in other words, bandwidth
will be continuously added and dropped.
The order in which ports are selected to be added and removed is controlled by a priority setting; when SCS
bandwidth needs change, ports with the highest priority are the first to be added and the last to be removed.
Bandwidth is controlled by the host that initiates the call. If the SCS initiates a call, it controls the bandwidth
for each site. If the SCS receives an incoming call, the bandwidth is controlled by the remote host.
The SCS will always use at least one port for a connection, even if the traffic is below the “remove
bandwidth” threshold. If this is not desired behavior, the last connection can be controlled by the idle timer.
Note:
To configure the idle timer, see Set/Define Server Inactivity on page 12-118.
5.3.2 Disadvantages of Additional Bandwidth
Increasing bandwidth by bringing up additional links has two disadvantages: increased cost and reduced
resources. Phone rates will go up as more phone lines are used, and fewer ports will be available for other
purposes. Assess your needs carefully before increasing bandwidth.
Summary of Contents for SCS
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Page 171: ...Modem Sharing Examples 10 6 ...
Page 314: ...Command Reference Service Commands 12 110 ...
Page 403: ...Show 802 11 Errors Rightmost Number B 5 00000002 Internal error 00000001 Internal error ...
Page 424: ...Index 13 ...