bmk@cbnews.ATT.COM (bernard.mckeever) (11/29/89)
Let's see now. Who uses more bandwidth, a voice call or a modem call? If both calls are direct dialed [not private line] the useable frequency range of the voice signal is approximately 250 Hz to 3500 Hz. If this voice signal is sent over digital facilities, both signals require one time slot, or 64 Kbs. It is possible to use ADPCM to reduce the required bit rate to 32 Kbs, but this is not often used in the "public" network. At one time, the Bell System would support data rates of 4800 baud over switched facilities and 9600 baud over private lines. Today, you can order service that allows 56 Kbs of switched digital data over a portion of the public network. Next. Special Access Code 710 was used for 4 row TWX in the NE portion of the US of A. The last I knew all the old TWX codes except 610 were to be recovered and used as Area Codes and/or Central Office codes. White Plains. Boy do I remember that place. I worked in a class 3/4/5 office across the river from them and you had to feel sorry for anybody who worked in a complex with several hundred switchmen. The place was a mad house. Can't say much about international DA but can vouch for the language problem. An office I worked in took all repair calls for the state after the repair bureaus closed. 611 was the valid repair number for many outstate offices and 116 was the inward international code used to reach the Lakewood IOC. Several times a night we would answer what looked like a repair call and wound up with an operator from overseas who spoke English as a third language. My vote for the best TELCO....No comment but some of the smaller ones have great names. [Moderator's Note: I know what code 710 *was* used for. But what is it used for *now*? Harry Newton in [Teleconnect Magazine] said it is now assigned for 'Government Special Services'. What does that mean? PT]