Polycom HDA50, Administrator'S Manual

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Service Providers
Polycom, Inc. 39
● Loopback types:
rtp-media-loopback
and
rtp-packet-loopback
● Loopback packet formats:
encaprtp
,
loopbkprimer
When the device acts as a loopback mirror, it always sends primer packets so that incoming packets can
get through NAT/Firewall. The media loopback feature is controlled by the following parameters (in the
Phone Port – Calling Features
section):
● AcceptMediaLoopback – Enable device to accept incoming call that requests media loopback.
Default is YES.
● MediaLoopbackAnswerDelay – The delay in ms before the device answers a media loopback call.
Default is 0.
● MediaLoopbackMaxDuration – The maximum duration to allow for an incoming media loopback
call. Default is 0, which means the duration is unlimited.
The device rejects an incoming media loopback call if:
● Phone port is off-hook.
● Phone port is ringing.
The device terminates an inbound media loopback call already in progress when:
● Phone port is off-hook.
● Phone port is ringing.
The outbound Media Loopback Call is not subjected to call duration limit; it lasts until the user hangs up or
until the called device ends the call.
For more information on general ITSP parameters, see the ITSP Profile A & B (General and SP Info
Settings) Parameter Guide table in the Parameter Reference Guide section.
For more information on ITSP SIP settings parameters, see the ITSP SIP Settings Parameter Guide table
in the Parameter Reference Guide section.
For more information on ITSP RTP settings parameters, see the ITSP RTP Settings Parameter Guide table
in the Parameter Reference Guide section.
Using SP
n
as a Proxy for a SIP IP Phone
An SP service can be set up as a proxy for a legacy IP phone to allow the phone to access the OBiTALK
installed on the device. This proxy mode of operation must be explicitly enabled in the SP’s configuration on
the device. It is disabled by default. The IP phone using this proxy service is known as the
local_client
of the
SP service. It must be installed on the LAN side of the device.
In this mode, SP
n
accepts SIP Registration from the client device from the LAN side, which must be using
the same user-id and password as this SP
n
’s AuthUserName and AuthPassword parameters for
authentication. This client device can also send SIP INVITE to the device at this SP to make calls; this SP’s
InboundCallRoute must be set up with the proper routing rule to handle calls from the
local_client
.
The SIP Proxy Server parameter on the client device must be sent to:
<obi-number>.pnn.obihai.com:<spn-user-agent-port>
where
<obi-number>
is the 9-digit OBi number of this device, and
<spn-user-agent-port>
is SP
n
’s
X_UserAgentPort parameter.