H.320

Also known as Px64.The ITU-T umbrella standard for videoconferencing and multimedia communications over narrowband ISDN (N-ISDN) bearer (B) channels at bit rates from 64 kbps to 1.920

Mbps, in increments of 64 kbps.Video compression makes use of codecs defined in H.261.Video formats include Common Intermediate Format (CIF), which is optional, and Quarter-CIF (QCIF), which is mandatory in compliant codecs. CIF supports resolution of 352 × 288 pixels, and QCIF supports resolution of 176 × 144 pixels, which is exactly 1⁄4 the resolution of CIF. Frame rates are 30 frames per second (fps), or lower. Audio coding and compression recommendations include G.711, which is pulse code modulation (PCM) at 64 kbps. G.722 is high fidelity adaptive differential pulse code modulation (ADPCM) transmitting up to a 7 kHz range and compressing voice at 48/56/64 kbps. G.728 specifies low delay code-excited linear prediction (LD-CELP) running in the 3 kHz range and compressing voice at 16 kbps.

The balance of the specification (H.221, H.230, and H.242) addresses techniques for call setup and teardown, data framing and multiplexing, and various other operational and administrative functions. See also

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• RSS (Really Simple Syndication or Rich Site Summary)
• RSVP (Resource Reservation Protocol)
• RTCP (Real Time Control Protocol)
• RTF (Rich Text Formatting)
• RTM (Ready To Market)
• RTP (Real Time Transport Protocol)
• rt (real-time)
• RTSP (Real-Time Streaming Protocol)
• RTS (Request To Send)
• rt-VBR (real-time Variable Bit Rate)
• rule of thumb
• rule of thumb
• rules of engagement
• rules of engagement
• run-length encoding
• runt
• Rural and High Cost Program
• Rural Health Care Corporation (RHC)
• Rural Health Care Program
• Réseaux IP Européens Network Coordination Center (RIPE NCC)
• S
• SAN (Storage Area Network)
• SAPI (Service Access Point Identifier)
• SAR (Segmentation And Reassembly)
• satellite