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Cisco WAN Manager User’s Guide
Version 10.5, Part Number 78-12945-01 Rev. D0, August 2003
Chapter7 Service Class Template Manager Functional Interaction
•Explicit Rate Sampling: I n dicates whether Explic it Rate Sampling (ERS) is e na bled or disabled.
Range and units: 1=enabled; 2=disabled.
•Random Early Discard Selection(RED): RED will drop packets from queues on a random basis in
order to avoid buffer ove rflo w. RED is accomplished by dropping pac ket s on a rando m bas is, whi ch
is determined statistically, when th e me an queue depth exceeds a thre s hold ove r a p er io d o f tim e,
effectively advising the packet source rou ter t o de creas e it s p ack et ra te.
•RED Threshold: Random Early Discard Threshol d: T he thresh old a t which t he COSB Ra ndom Earl y
Discard (RED) is activated. This threshold is a percentage of the MAX_CELL THRESH for the
connection. 1000000 is equal to 100%. Range and units: 0-1000000.
•RED Probability: Random Early Discard Probability Factor: The mantissa value of probability for
maximum discard when RED is act ivated. D ete r min ed as 1/ 2^ <valu e> .
•WFQ: Weighted Fair Queuing. WFQ q ue ue s tr affic in s e pa rate queues, according to tr affic cl ass
definition, guaranteeing e ach queue some p ort ion of the t otal available bandwidth. WFQ recognizes
when a particular queue is not fully utilizing its allocated band w id th an d p or t io ns th at cap acity out
to the other queues on a proportionate basis. This is done by portioning out a vailable bandwidth on
the basis of individual information flows according to their message parameters.
•Best Effort: A Quality of Servic e Class in which no specific t raffic pa ra m ete rs and no absolute
guarantees are provided. Best Effort in cl ud es UB R an d A BR S e rv ic e Types.
•Discard Alarm Enable: Indicates wh et h er D isca rd Al arm has been enabled or disable d. Ra nge and
units: 1=enabled; 2=dis able d.
•Discard Alarm Threshold: Indicates t he D isc ar d Alar m T hreshold.
•Cell Loss Ratio: A negoti ated Quality of Servic e p a r ame ter in an ATM network. This para meter
indicates a ratio of lost c ell s to t ot al tr an smitted cells.
Each tab displays parameters in table f ormat, with the above criteria and its associate d data presented in
each column of a given table. Each row represents a unique Servic e Type, including: ABR, CBR, UBR,
VBR and VSI Signal.
By selecting a row on the table, the corresponding CoSB parameters are also displayed in the bottom
CoSB panel.
Except for Service Type and Service Ca tegor y co lu m ns , m o st co lu m n s un d er ea ch V C tab h ave d rop
down boxes which allow authorized u ser s t o ed it and modify cells as needed.
Cells are editable and c a n be changed ONLY if both of t he following conditions are met:
•The user has security permissio ns to co n figur e SC T files, and
•The SCT file is not downloaded and/or not associated
CoSB Panel
The CoSB panel displays CoSB parameters by CoSB Number. The data in this panel reflects the row
selection of the table on t he VC or top pa nel . The se pa ra mete rs a re cu rrent ly o rga ni zed into t hr ee g rou ps:
Rate & Priority, Threshold, and Miscella ne ous.
In the Rate & Priority category, the following parameters can be modified:
•Minimum Rate: The minimu m r at e a t which this COSB will b e se rviced in order to guaran t ee i ts
minimum and maximum bandwidth requirements.
•Maximum Rate: The minim u m r at e at which this COSB wi ll b e serviced in order to gu aran tee its
minimum and maximum bandwidth requirements.