# msp_ENDPOINT_RTPFDX_RTP_PKTSZ_CTRL

This video-specific structure fine-tunes CG board performance by controlling the RTP packetization parameters transmitted by MPEG-4, H.263, and H.264 RTP endpoints from the PSTN side to the IP side of the 3G-324M Interface.

Use msp_ENDPOINT_RTPFDX_RTP_PKTSZ_CTRL with the MSP_ENDPOINT_RTPFDX_RTP_PKTSZ_CTRL command and the MSP_QRY_RTPFDX_VIDEO_RTP_PKTSZ_CTRL query, which are described in Adjusting RTP packetization parameters.

Note: NMS recommends that you keep the default values for this structure, unless you must fine-tune performance for a video tromboning configuration.

#### Definition

typedef struct tag_msp_ENDPOINT_RTPFDX_RTP_PKTSZ_CTRL
{
DWORD pktMaxSz;
DWORD aggThreshold;
DWORD enableAggregation;
} msp_ENDPOINT_RTPFDX_RTP_PKTSZ_CTRL;

#### Fields

Field name | Default | Description
--- | --- | ---
pktMaxSz | 1400 | Sets the maximum transmission size in bytes for the payload of RTP packets being transmitted from the specified video RTP endpoint. Valid values are: 0 - Uses the default size (1400). -1 - Leaves the current value of pktMaxSz unmodified. A value between MIN_PKTMAXSIZE and 1440, inclusive.
aggThreshold | 700 | Sets the aggregation threshold in bytes for the transmission of aggregated packets. This parameter is not used for H.264 endpoints. Valid values are: 0 - Uses the default threshold (700). -1 - Leaves the current value of aggThreshold unmodified. A value between MIN_AGGTHRESHOLD and 1440, inclusive.
enableAggregation | Enabled | Indicates whether the video RTP endpoint aggregates H.263 GOB frames (for H.263 endpoints) or MPEG-4 Video Packets (for MPEG-4 endpoints) before transmitting them. This parameter is not used for H.264 endpoints. If aggregation is enabled, then the RTP endpoint aggregates consecutive GOB/Video Packet frames, until adding another GOB/Video Packet frame causes the outgoing RTP packet to exceed the bytes specified in the aggThreshold field. Valid values are: 0 - Disables the aggregation of GOB/Video Packet frames. -1 - Leaves the current value of the enableAggregation field unmodified. A value other than -1 or 0 - Enables the aggregation.