Specifications

Engineering Guidelines
20
The 3300 ICP as a Trunk Tandem
When the 3300 ICP acts as a Trunk Tandem, it functions similar to that described for the gateway
unit. Typically, this configuration is applied where there is already an established (TDM) PBX
network where the ICP units are being used for toll-bypass, or as an alternative route to the PSTN.
As with the gateway unit, the 3300 ICP does not have end users directly connected. The heavy
performance load and/or the limited number of E2T channels will restrict the capacity of this
configuration. The connections for a tandem configuration may be TDM trunk to TDM trunk, IP
trunk to TDM trunk, SIP trunk to TDM trunk, or IP trunk to SIP trunk. The first three require a
TDM gateway and are limited by the number of TDM channels available (same as the TDM
gateway), but the last configuration does not and will be limited only by performance.
MiVoice Business, 3300 ICP and ACD
A typical call center (ACD) installation consists of several separate components which integrate
to make up the complete system.
• ACD controller may be either MiVoice Business on a server platform (MXe Server,
MiVoice Business for ISS, MiVoice Business Multi-instance, Virtual MiVoice Business) or
one of several 3300 ICP platforms. This can either be all functions in one standalone
controller, or a network of trunk gateways and agent controllers.
• Contact Center Manager (CCM), for reporting and some interactive functions.
• Interactive Voice Response (IVR), the auto-attendant function, which may also act as a
source for recorded announcements (RADs).
When MiVoice Business and 3300 ICP are used for ACD applications, there are several factors
that must be considered in determining the capacity limitations. The performance of the
controller will be limited because of the high number of calls made in comparison to a system
with normal office traffic. In addition, the performance cost of each call will be much higher, to
account for IVR interaction in the call (including RAD playback) and for agent skills groups and
multiple path queues. Because agents are connected to trunks most of the time, the number
of E2T channels will be critical to the number of agents and/or trunks that can be supported.
It is expected that most MiVoice Business and 3300 ICP installations will use IP phones for the
agents but it is also possible with some 3300 ICP controllers to use TDM phones (DNIC or
ONS). Where they can be used, TDM phones are included with IP phones in the total agent
quantity. In some cases External Hot Desk Agents (EHDA) may be used, and these will add
significant overhead to the performance of the system, reducing the total number of agents
supported. In a standalone system with a 3300 ICP controller, the number of agents with IP
phones is limited by the number of E2T channels available, but since DNIC and ONS phones
do not require E2T resources to connect to a TDM trunk, it is possible to put more of them in
a standalone system. Conversely, an agent group controller connected to multiple trunk
gateways can handle more IP phones than TDM phones since the IP phones in this case do
not need the E2T resources and the TDM phones do.
SIP trunks provide an alternate means of connecting to the PSTN. These will be used most often
with MiVoice Business for ISS controllers, although it is also possible to use them with 3300 ICP
controllers.