User's Manual

Avaya Branch Gateway Manager 10.0 Page 248
15-601011 Issue 29r (Friday, November 02, 2012)B5800 Branch Gateway
· Encryptions: Default = RTP
This setting allows selection of which parts of a media session should be protected using encryption. The
default is to encrypt just the RTP stream (the speech).
· Authentication: Default = RTCP
This setting allows selection of which parts of the media session should be protected using authentication. The
default is authenticate just the RTCP stream (call control signals).
· Replay Protection:
Displays the options for the SRTP window size. Currently not adjustable.
· SRTP Window Size: Default = 64.
· Crypto Suites: Default = SRTP_AES_CM_128_SHA1_80 and SRTP_AES_CM_128_SHA1_32.
· VoIP Silence Suppression: Default = Off
When selected, this option will detect periods of silence on any call over the line and will not send any data during
those silent periods. This feature is not used on IP lines using G.711 between systems. On trunk's between networked
systems, the same setting should be set at both ends.
·
· RE-Invite Supported: Default = Off.
When enabled, Re-Invite can be used during a session to change the characteristics of the session. For example when
the target of an incoming call or a transfer does not support the codec originally negotiated on the trunk. Requires the
ITSP to also support Re-Invite.
· Use Offerer's Preferred Codec: Default = Off.
Normally for SIP calls, the initiator of the calls sends a SIP offer which includes the codecs that they support in order of
preference. The SIP response includes the codec the remote end wants to use for the call. This option can be used to
override that behaviour and use the codec preference offered by the caller. This option is only used when the IP Office
sends INVITES.
· Codec Lockdown: Default = Off.
Supports RFC 3264 Section 10.2 when RE-Invite Supported and Codec Lockdown are enabled. In response to a
SIP offer with a list of codecs supported, some SIP user agents supply a SDP answer that also lists multiple codecs.
This means that the user agent may switch to any of those codecs during the session without further negotiation. The
system does not support multiple concurrent codecs for a session, so loss of speech path will occur if the codec is
changed during the session. If codec lockdown is enabled, when the system receives an SDP answer with more than
one codec from the list of offered codecs, it sends an extra re-INVITE using just a single codec from the list and
resubmits a new SDP offer with just the single chosen codec.
· PRACK/100rel Supported: Default = Off. Release 6.2
When selected, supports Provisional Reliable Acknowledgement (PRACK) on SIP trunks. Enable this parameter when
you want to ensure that provisional responses, such as announcement messages, have been delivered. Provisional
responses provide information on the progress of the request that is in process. For example, while a cell phone call is
being connected, there may be a delay while the cell phone is located; an announcement such as “please wait while we
attempt to reach the subscriber” provides provisional information to the caller while the request is in process. PRACK,
which is defined in RFC 3262, provides a mechanism to ensure the delivery of these provisional responses.
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