System information

Polycom® Unified Communications Deployment Guide for Cisco Environments
64
Design Considerations
Dial Plan
When integrating Polycom DMA with VCS, it is important to keep in mind that they are both call
control entities. Dial plan considerations will be a vital aspect of the design prior to
implementation and often times must also account for the telephony or IP PBX solution in the
environment. Creating an organized numbering scheme and coordinating extensions to be in
contiguous (summarizable) blocks on each system is ideal when possible. In the case of SIP
and SIP Uniform Resource Identifiers (URI), the domain of each system must be configured as
well. If VCS is responsible for the subdomain abc.company.com, it may be advantageous to
have DMA be responsible for its own subdomain, for example, xyz.company.com. In the case of
H.323, naming conventions for H323-IDs should also be considered.
Call Admission Control
The Call Admission Control (CAC) for each system will be configured and administered
separately. Care should be taken to avoid having different endpoints from the same site or
location registered with both DMA and VCS unless the bandwidth restrictions take this into
account.
Protocol Conversion
When designing the integration between VCS and DMA, consider use cases where either DMA
or VCS will be performing H.323-to-SIP or SIP-to-H.323 conversion services. VCS utilizes a
licensing method for each conversion that occurs, so it is important to note when a particular
use case will invoke a license. DMA does not license these calls separately, but has separate
capacity limits for these calls.
Note: DMA System Getway Function Usage
The DMA system’s gateway function is used only for calls to registered endpoints, SIP
peers, and H.323 gatekeepers. It’s not used for calls to virtual meeting rooms (VMRs),
virtual entry queues (VEQs), external addresses, or IP addresses.
See the Polycom DMA 7000 System Operations Guide for more information about protocol
conversion capabilities and limits on the Polycom DMA system.
See the VCS Configuration Guides
for more information about VCS traversal licenses.