# MSPP queries and commands for the 3G-324M Interface

This topic describes the following queries and commands to use with the 3G-324M Interface:

- Queries for all video endpoints

- Query for H.264 endpoints

- Query for the video channel jitter buffer filters

- Commands for all video endpoints

- Commands for MPEG-4 and H.264 endpoints only

- Commands for H.263 endpoints only

- Commands for the video channel jitter buffer filters

## Queries for all video endpoints

The following MSPP queries can be sent to MPEG-4, H.263, and H.264 RTP endpoints:

Query (associated structure) | Description
MSP_QRY_RTPFDX_STATUS MSP_QRY_RTPIN_STATUS MSP_QRY_RTPOUT_STATUS (msp_ENDPOINT_RTPFDX_STATUS) | Returns information about the specified full-duplex or simplex RTP endpoint filter state. For more information, see the MSPP Developer's Reference Manual.
MSP_QRY_RTPFDX_VIDEO_RTP_PKTSZ_CTRL MSP_QRY_RTPOUT_VIDEO_RTP_PKTSZ_CTRL (msp_ENDPOINT_RTPFDX_RTP_PKTSZ_CTRL) | Returns the packet size and aggregation parameter settings for the packets transmitted by the specified full-duplex or simplex send RTP endpoint from the PSTN to the IP side of the gateway. For more information, see Adjusting RTP packetization parameters.

## Query for H.264 endpoints

The following MSPP query can be sent to H.264 RTP endpoints:

Query (associated structure) | Description
MSP_QRY_RTPFDX_H264_TX_STATUS MSP_QRY_RTPOUT_H264_TX_STATUS (msp_ENDPOINT_RTPFDX_H264_TX_STATUS) | Returns transmit packetization status information for H.264 full duplex and simplex send endpoints. For more information, see Querying an H.264 endpoint for transmit status.

## Query for the video channel jitter buffer filters

The following MSPP query can be sent to the video channel jitter buffer filters:

Query (associated structure) | Description
MSP_QRY_JITTER_VIDEO_GET_STATE (msp_FILTER_JITTER_VIDEO_STATE) | Returns the status of the video jitter buffer. For more information, see Querying the video jitter buffer state.

## Commands for all video endpoints

The following MSPP commands can be sent to MPEG-4, H.263, and H.264 video RTP endpoints:

Command (associated structure) | Description
MSP_CMD_RTPFDX_CALC_SKEW_OFFSET MSP_CMD_RTPIN_CALC_SKEW_OFFSET (msp_ENDPOINT_RTPFDX_ENABLE_SKEW_CALC) | Enables the calculation of skew offsets used for audio/video synchronization purposes for the specified full-duplex or simplex receive audio and video RTP endpoints. For more information, see Using RTCP for audio/video synchronization.
MSP_CMD_RTPFDX_CONFIG MSP_CMD_RTPIN_CONFIG MSP_CMD_RTPOUT_CONFIG (msp_ENDPOINT_RTPFDX_CONFIG) | Sets configuration parameters for the specified full-duplex or simplex RTP endpoint. This command also sets timestamp frequencies for RTP endpoints. For more information, see the MSPP Developer's Reference Manual and Setting timestamp frequencies for full-duplex RTP endpoints.
MSP_CMD_RTPFDX_IFRAME_NOTIFY_CTRL MSP_CMD_RTPIN_IFRAME_NOTIFY_CTRL MSP_CMD_RTPOUT_IFRAME_NOTIFY_CTRL (msp_ENDPOINT_RTPFDX_IFRAME_NOTIFY_CTRL) | Enables or disables I-frame notification for the specified full-duplex or simplex RTP endpoint. For more information, see Enabling I-frame notification.
MSP_CMD_RTPFDX_LINK_EVENTS MSP_CMD_RTPOUT_LINK_EVENTS (msp_ENDPOINT_RTPFDX_LINK_EVENTS) | Enables or disables reporting link availability transitions through unsolicited events for the specified full-duplex or simplex send RTP endpoint. For more information, see the MSPP Developer's Reference Manual.
MSP_CMD_RTPFDX_MAP MSP_CMD_RTPIN_MAP (msp_ENDPOINT_RTPFDX_MAP) | Assigns a payload ID to a vocoder for the specified full-duplex or simplex receive RTP endpoint. For more information, see the MSPP Developer's Reference Manual.
MSP_CMD_RTPFDX_RTCP_EVENTS MSP_CMD_RTPIN_RTCP_EVENTS MSP_CMD_RTPOUT_RTCP_EVENTS (msp_ENDPOINT_RTPFDX_RTCP_EVENTS) | Enables or disables reporting RTCP events through unsolicited events for the specified full-duplex or simplex RTP endpoint. For more information, see the MSPP Developer's Reference Manual.
MSP_CMD_RTPFDX_SET_VID_TX_PID MSP_CMD_RTPOUT_ SET_VID_TX_PID (msp_ENDPOINT_RTPFDX_SET_VID_TX_PID | Sets a transmit payload ID for the specified full-duplex or simplex send video RTP endpoint. For more information, see Setting the video transmit RTP payload ID.
MSP_CMD_RTPFDX_VIDEO_RTP_PKTSZ_CTRL MSP_CMD_RTPOUT_VIDEO_RTP_PKTSZ_CTRL (msp_ENDPOINT_RTPFDX_RTP_PKTSZ_CTRL) | Sets the maximum packet size and aggregation threshold, and indicates whether aggregation takes place for the packets transmitted by the specified full-duplex or simplex send RTP endpoint from the PSTN to the IP side of the gateway. For more information, see Adjusting RTP packetization parameters.
MSP_CMD_RTPFDX_VIDEO_SKEW_TIME MSP_CMD_RTPOUT_ VIDEO_SKEW_TIME (msp_ENDPOINT_RTPFDX_SET_VID_SKEW) | Sets a video skew value to send to the IP destination. The skew value can be used for audio/video synchronization purposes for the specified full-duplex or simplex send video RTP endpoint. For more information, see Enabling RTP video send endpoints to send video skew values to the IP destination.
MSP_CMD_RTPFDX_RTTS_CTRL MSP_CMD_RTPOUT_ RTTS_CTRL (msp_ENDPOINT_RTPFDX_RTTS_CTRL) | Enables or disables reporting the real-time timestamping feature for the specified full-duplex or simplex send RTP endpoint. For more information, see Configuring real-time timestamp generation.

## Command for MPEG-4 and H.264 endpoints only

The following MSPP command can be sent to MPEG-4 and H.264 video RTP endpoints only:

Command (associated structure) | Description
MSP_CMD_RTPFDX_OUT_OF_BAND_DCI MSP_CMD_RTPOUT_OUT_OF_BAND_DCI (msp_ENDPOINT_RTPFDX_OUT_OF_BAND_DCI) | Optionally replaces in-band DCI with commanded out-of-band DCI for the specified full-duplex or simplex send RTP endpoint. For more information, see Inserting out-of-band DCI into the video bit stream.

## Commands for H.263 endpoints only

The following MSPP commands can be sent to H.263 video RTP endpoints only:

Command (associated structure) | Description
MSP_CMD_RTPFDX_DISCARD_PENDING_PFRAMES MSP_CMD_RTPIN_DISCARD_PENDING_PFRAMES | Discontinues forwarding partial frames from IP to PSTN, until an incoming I-frame is detected on the specified full-duplex or simplex receive H.263 RTP endpoint. For more information, see Discarding leading partial frame video packets.
MSP_CMD_RTPFDX_H263_ENCAP_CTRL MSP_CMD_RTPOUT_H263_ENCAP_CTRL (msp_ENDPOINT_RTPFDX_H263_ENCAP_CTRL) | Sets the RFC encapsulation type used for the specified full-duplex or simplex send H.263 RTP endpoint. For more information, see Setting the H.263 RFC encapsulation type.
MSP_CMD_RTPFDX_STOP_VIDEO_RX MSP_CMD_RTPIN_STOP_VIDEO_RX | Stops the video transmission in the direction of the PSTN for the specified full-duplex or simplex receive H.263 RTP endpoint, after the current frame has been fully received. For more information, see Ensuring a smooth transition when the video source changes.

## Commands for the video jitter buffer filters

The following MSPP commands can be sent to MPEG-4, H.263, and H.264 video channel jitter filters only:

Command (associated structure) | Description
MSP_CMD_JITTER_CHG_VIDEO_LATENCY (msp_FILTER_JITTER_VID_LATENCY) | Changes the configured video jitter buffer latency. The maximum latency is 2000 ms (2 seconds). For more information, see Setting the video jitter buffer latency.
MSP_CMD_JITTER_NORMALIZE_VIDEO_LATENCY_BUF | Removes the excess video packets that accumulate above the configured latency in the video jitter buffer. The configured latency value remains in the video jitter buffer after you remove the excess video packets. For more information, see Removing excess video packets from the video jitter buffer.
MSP_CMD_JITTER_PURGE_VIDEO_LATENCY_BUF | Removes all data from the video jitter buffer, including all video packets and the configured video latency value. For more information, see Purging the video jitter buffer.