Resource sizing
Issue 3.4.1 June 2005
175
Processing occupancy
The Busy Hour Call Attempt (BHCA) rate of a system is the total number of calls that are
attempted within that system, during its busy hour. This is distinct from the Busy Hour Call
Completion (BHCC) rate of a system, which counts only those calls that have actually been
completed. The call capacity of a system refers to its BHCC rate.
In Communication Manager products, server occupancy (or processor occupancy, as
applicable) can be broken down into three categories: static occupancy, Call Processing (CP)
occupancy, and system management (SM) occupancy. The static component refers to
keep-alive processes, the CP component refers to processes that are required to set up and
tear down calls (as well as vectoring operations, in the case of call centers), and the SM
component refers to background maintenance operations and system audits. In theory, static
occupancy is a fixed overhead, and CP occupancy is directly proportional to the call rate. SM
occupancy is allocated on an as-needed basis, such as for periodic maintenance functions.
However, if the overall server occupancy exceeds a particular threshold, SM operations are
postponed until a quieter traffic period.
Usually, the relationship between the sum of static and CP occupancy, as a function of BHCC, is
linear, with a positive y-intercept, as illustrated in
Figure 60: Relationship Between Processing
Occupancy and BHCC Rate
. The slope of the line corresponds to the average processing cost
per call, and the intercept corresponds to the idle (that is, no-load) occupancy. The average
processing cost per call depends on the mix of calls that is being handled by the system, and
how complex each type of call is. For general business calls, nearly all of the CP occupancy is
associated with setting up and tearing down calls. The call processing that is required for
maintaining the call once it has been established is negligible in comparison, regardless of how
long the call lasts. In a call center, the additional cost of processing vectoring steps throughout
the lifetime of a call must also be considered.
Figure 60: Relationship Between Processing Occupancy and BHCC Rate
Proc
essing O
ccup
a
nc
y
(CP
+
S
tat
ic)
BHCC Rate
Idle (No-Load)
Occupancy
Содержание Application Solutions
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Страница 20: ...About This Book 20 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 21: ...Issue 3 4 1 June 2005 21 Section 1 Avaya Application Solutions product guide ...
Страница 22: ...22 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 74: ...Avaya Application Solutions platforms 74 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 106: ...Call processing 106 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 124: ...Avaya LAN switching products 124 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 139: ...Issue 3 4 1 June 2005 139 Section 2 Deploying IP Telephony ...
Страница 140: ...140 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 186: ...Traffic engineering 186 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 204: ...Security 204 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 214: ...Voice quality network requirements 214 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 228: ...Avaya Integrated Management 228 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 239: ...Reliability Issue 3 4 1 June 2005 239 Figure 69 S8700 Media Server in a high reliability configuration ...
Страница 274: ...Reliability and Recovery 274 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 275: ...Issue 3 4 1 June 2005 275 Section 3 Getting the IP network ready for telephony ...
Страница 276: ...276 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 350: ...Implementing Communication Manager on a data network 350 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 356: ...Network recovery 356 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 366: ...Network assessment offer 366 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 367: ...Issue 3 4 1 June 2005 367 Appendixes ...
Страница 368: ...Appendixes 368 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 394: ...Access list 394 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 414: ...DHCP TFTP 414 Avaya Application Solutions IP Telephony Deployment Guide ...