Cisco Unified MeetingPlace, Release 7.0 -- Media Parameters Page
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1. RFC-2833, which is negotiated and can be disabled | 1. RFC-2833, which is negotiated and can be disabled | ||
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2. KPML, which is negotiated and cannot be disabled | 2. KPML, which is negotiated and cannot be disabled | ||
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3. In-band DTMF tones, which is not negotiated but can be disabled (see "Enable in-band DTMF detection" setting) | 3. In-band DTMF tones, which is not negotiated but can be disabled (see "Enable in-band DTMF detection" setting) | ||
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RFC 2833 is a standard mechanism for transmitting keypad digits in-band in VoIP media packets. It is commonly used as an adjunct to SIP signaling. Most calls will negotiate either RFC 2833 (in band) or KPML<sup class="Footnote">8</sup> (out of band) depending on the capabilities of the user endpoint. | RFC 2833 is a standard mechanism for transmitting keypad digits in-band in VoIP media packets. It is commonly used as an adjunct to SIP signaling. Most calls will negotiate either RFC 2833 (in band) or KPML<sup class="Footnote">8</sup> (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), MeetingPlace will listen for RFC-2833 and not KPML. | + | |
+ | 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. | ||
Latest revision as of 20:31, 21 April 2010
Main page: Cisco Unified MeetingPlace, Release 7.0
Up one level: Reference Information
Use this page to modify audio and video settings. To find this page, click System Configuration > Call Configuration > Media Parameters.
Table: Field Reference: Media Parameters Page
Field | Description |
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Media Parameters | |
Audio RTP starting port |
The Media Server assigns RTP1/UDP2 ports starting from the specified value up to that value plus 1024. Modify this field only if required to conform with local firewall rules.
|
TTL |
Time-to-live value in the IP header of transmitted voice packets. Determines how many hops an IP packet can travel through the network before it is discarded.
|
QoS3 | |
Audio media IPv4
|
Differentiated Services (DiffServ) code point (DSCP) settings that determine the QoS for the audio and video media signaling, as defined in RFC 2475.
|
Echo Canceller4 | |
Window size (milliseconds) |
Range of echo return delay that the LEC will attempt to cancel.
|
Enable non-linear processing (NLP) |
NLP removes the small amount of residual uncanceled echo that inevitably passes through the echo canceller and may be useful for removing residual echo from acoustic or low-bandwidth voice codec (for example, ITU-T G.729) endpoints.
|
Enable comfort noise in NLP |
To help make the overall background noise level continuous, the NLP generates comfort noise.
|
Enable LEC w. G.729? |
Whether to enable LEC when G.729 is in use.
|
Minimum echo return loss (ERL) (dB) |
A lower ERL setting may help the LEC cancel loud echoes, but it increases the risk of distortion caused by clipping or squelching of the signal.
|
Bulk delay (milliseconds) |
This value is added to the Window size (milliseconds), so that the cancelled echo return delays will range from Bulk delay (milliseconds) to Bulk delay (milliseconds) + Window size (milliseconds). This allows the LEC to work on echoes that are outside the normal range in exchange for not canceling short-return-delay echoes.
|
Gain Control6 | |
Enable automatic gain control (AGC) |
AGC causes Cisco Unified MeetingPlace to dynamically adjust the input gain so the average energy matches a specific level. This is useful when various phones, or people in a conference room, produce different volume levels. Nevertheless, AGC can be problematic in cases where noise may be mistaken for voice.
|
AGC target level (dBm) |
The target energy level for the AGC algorithm is applied to all inputs. Make this number less negative to increase the average volume level. The default value of -18 is a typical level for telephony circuits.
|
Fixed gain (dB) |
The fixed input gain is applied to all inputs. Use positive numbers to increase the volume, and use negative numbers to decrease the volume. The default value of 0 leaves the input level alone.
|
Digits7 | |
Enable RFC 2833 detection |
There are three DTMF methods: 1. RFC-2833, which is negotiated and can be disabled
|
RFC2833 payload type |
Not supported. Appears only in Release 7.0.1. |
Enable in-band DTMF detection |
Whether to turn on the signal processing which looks for in-band acoustic DTMF9 tones in the input audio media stream. Note that DTMF works well only with the G.711 codec.
|
Jitter Buffer | |
Maximum 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.
|
Miscellaneous | |
Maximum conference speakers |
Maximum number of input lines that will be simultaneously mixed together in a meeting. A small value (2) reduces the background noise and echo, which is best for lecture-style meetings. A large value (4) is best for more interactive meetings.
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Footnotes:
1. RTP = Real-Time Transport Protocol
2. UDP = User Datagram Protocol
3. QoS = Quality of Service
4. The echo canceller parameters control the Line Echo Canceller (LEC), which reduces audible echo in meetings.
5. A system restart terminates all existing call connections. Proceed only during a scheduled maintenance period or during a period of extremely low usage. To restart the system, enter sudo mpx_sys restart in the CLI. For information about logging into the CLI, see Using the Command-Line Interface (CLI) in Cisco Unified MeetingPlace.
NOTE: When you restart the Web Server, all manual changes made to the registry are lost.
6. The gain control parameters apply a fixed or adaptive gain to all audio inputs.
7. The digits parameters control how keypad inputs are received.
8. KPML = Key Press Markup Language
9. DTMF = Dual Tone Multi-Frequency