Polycom 3725-76302-001LI manual About the Call Server Capabilities

DMA Operations Guide About the Call Server Capabilities

About the Call Server Capabilities

The Polycom DMA system’s Call Server capabilities provide gatekeeper functionality (if H.323 signaling is enabled), SIP proxy server and registrar functionality (if SIP signaling is enabled), XMPP server (if XMPP signaling is enabled), and bandwidth management.

Note

SIP and XMPP signaling are not supported in Maximum security mode. See “The

Consequences of Enabling Maximum Security Mode” on page 54.

The system can also function as an H.323 <-> SIP gateway.

Note

In H.323, DTMF tones are usually sent over the H.323 signaling path. In SIP, DTMF tones are usually sent over the media path as a special RTP payload packet (see RFC 4733). Because of this difference and because the DMA system isn’t in the media path, its gateway function doesn’t support DTMF transmission.

The gateway function also doesn’t support content sharing or AES encryption.

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.

In addition, the system can be integrated with a Juniper Networks Service Resource Controller (SRC) to provide bandwidth assurance services.

Call server configuration begins with enabling the desired signaling on each cluster’s Signaling Settings page. Other Call Server settings are shared across all systems in a supercluster and set on the Admin > Call Server pages.

Note

In an IPv4 + IPv6 environment, the Polycom DMA system gatekeeper prefers the IPv4 address for devices that register with both. For example, if endpoint A is a dual-stack device (that is, it supports both IPv4 and IPv6) and registers over IPv6 to a Polycom DMA system that’s also dual-stack, the RRQ (Registration Request) message informs the DMA gatekeeper of the endpoint's IPv6 and IPv4 addresses (as well as its E.164 alias, etc.).

If endpoint A dials the E.164 address of another dual-stack endpoint (endpoint B), DMA gives preference to the IPv4 address by sending endpoint B's IPv4 address in the ACF (Admission Confirm) message to endpoint A. Even though the initial ARQ and corresponding ACF were over IPv6, the expected behavior is that endpoint A will continue the H.323 signaling session to endpoint B over IPv4 since the DMAgatekeeper informed endpoint A of endpoint B's IPv4 signaling IP.

See also:

“Call Server Configuration” on page 237

238 Polycom, Inc.