Cisco Unified MeetingPlace, Release 7.0 -- Media Parameters Page
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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 |
---|---|
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 |
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 KPML8 (out of band) depending on the capabilities of the user endpoint. You can force the use of KPML by disabling RFC 2833, but this is typically not necessary.
|
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.
|
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.
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