Cisco Cisco Unified MeetingPlace 5.3 Guide D’Installation Rapide
Administration Center Page References for Cisco Unified MeetingPlace
Media Parameters Page
56
Digits
7
Enable RFC 2833 detection
There are three DTMP methods:
1.
RFC-2833, which is negotiated and can be disabled.
2.
KPML, which is negotiated and cannot be disabled
3.
In-band DTMF tones, which is not negotiated but can be disabled (see"Enable
in-band DTMF detection" setting)
in-band DTMF detection" setting)
RFC 2833 is a standard mechanism for transmitting keypad digits in-bandin VoIP
media packets. It is commonly used as an adjunct to SIP signaling.Most calls will
negotiate either RFC 2833 (in band) or KPML
media packets. It is commonly used as an adjunct to SIP signaling.Most calls will
negotiate either RFC 2833 (in band) or KPML
8
(out of band) depending on the
capabilities of the user endpoint.
If both RFC-2833 and KPML are negotiated (implying that RFC-2833 was enabled),
Cisco Unified MeetingPlace will listen for RFC-2833 and not KPML. You can force the
use of KPML by disabling RFC 2833 if you are trying to validate KPML. Otherwise,
disabling RFC-2833 is typically not necessary as most calls will not notice a difference.
If you do notice a difference it may be due to Cisco Unified Communications Manager
inserting a MTP to translate RFC-2833 to KPML. This happens if a trunk or endpoint
does not support out-of-band signaling. Depending on the setup, MTP insertion may
result in loss of video or, if you run out of MTP resources, call failure.
Cisco Unified MeetingPlace will listen for RFC-2833 and not KPML. You can force the
use of KPML by disabling RFC 2833 if you are trying to validate KPML. Otherwise,
disabling RFC-2833 is typically not necessary as most calls will not notice a difference.
If you do notice a difference it may be due to Cisco Unified Communications Manager
inserting a MTP to translate RFC-2833 to KPML. This happens if a trunk or endpoint
does not support out-of-band signaling. Depending on the setup, MTP insertion may
result in loss of video or, if you run out of MTP resources, call failure.
Default: Yes
Enable in-band DTMF detection
Whether to turn on the signal processing which looks for in-band acoustic DTMF
9
tones
in the input audio media stream. Note that DTMF works well only with the G.711
codec.
codec.
Recommendation: Enter Yes to support terminals that lack another signaling
mechanism, including RFC 2833, KPML, or H.245. Enter No if you find that
Cisco Unified MeetingPlace responds to voices as if they were keypad inputs (talk off).
mechanism, including RFC 2833, KPML, or H.245. Enter No if you find that
Cisco Unified MeetingPlace responds to voices as if they were keypad inputs (talk off).
Default: Yes
Jitter Buffer
Maximum size (milliseconds)
Minimum size (milliseconds)
Maximum and minimum lengths of time, in milliseconds, that the jitter buffer holds
voice packets. A large jitter buffer helps the system accurately reassemble the media
stream, but it adds to perceived latency.
voice packets. A large jitter buffer helps the system accurately reassemble the media
stream, but it adds to perceived latency.
Jitter refers to the variation in the delay of received packets. When voice data is sent
across the network, the packets are sent in a continuous stream with the packets spaced
evenly apart. Due to network congestion, improper queuing, or configuration errors, the
delay between each received packet can vary instead of remaining constant. Some
packets may even arrive out of order or not arrive at all.
across the network, the packets are sent in a continuous stream with the packets spaced
evenly apart. Due to network congestion, improper queuing, or configuration errors, the
delay between each received packet can vary instead of remaining constant. Some
packets may even arrive out of order or not arrive at all.
A higher
Maximum size (milliseconds)
helps the system adapt to poor conditions. A
lower value may be better for interactive conversations, where an occasional dropped
packet may be preferable to long latency.
packet may be preferable to long latency.
The
Minimum size (milliseconds)
is the starting jitter buffer size. The closer this value
is to the typical jitter on the network, the quicker the system adapts, but this adds
directly to latency.
directly to latency.
Maximum size (milliseconds)
default: 250
Minimum size (milliseconds)
default: 30
Table 36
Field Reference: Media Parameters Page (continued)
Field
Description