IBM 729 the tape reel. A 3/4 inch gap between records allowed the mechanism enough time to stop the tape. Initial tape speed was 75 inches per second (2.95 m/s) and recording density was 200 characters per inch, giving a transfer speed of 120 kbit/s. Later 729 models supported 556 and 800 characters/inch (transfer speed 480 kbit/s). At 200 characters per inch, a single 2400 foot tape could store the equivalent of some 50,000 punched cards (about 4,000,000 six-bit bytes, or 3 MByte). The 729 series was superseded by 9 track tape drives introduced with the IBM System/360. The IBM 729 I
G.729 11.8 kbit/s (Annex E, G, H, I, C+) for worse and better speech quality, respectively. G.729 has been extended with various features, commonly designated as G.729a and G.729b: Dual-tone multi-frequency signaling (DTMF), fax transmissions, and high-quality audio cannot be transported reliably with this codec. DTMF requires the use of the named telephony events in the RTP payload for DTMF digits, telephony tones, and telephony signals as specified in RFC 4733. G.729a is a compatible extension of G.729, but requires less computational power. This lower complexity, however, bears the cost of marginally reduced speech quality. G.729a was developed by a consortium