case scenerio, quoting doubles the amount of data (Free web design)
case scenerio, quoting doubles the amount of data to be transmitted, although compression done by the hardware may compensate. Lines that can transmit arbitrary 8-bit characters are usually called 8-bit clean. This is the case for all TCP connections, as well as for most modem connections. Taylor UUCP 1.06 supports a wide variety of UUCP protocols. The most common of these are: g This is the most common protocol and should be understood by virtually all uucicos. It does thorough error checking and is therefore well suited for noisy telephone links. g requires an 8-bit clean connection. It is a packet-oriented protocol that uses a sliding-window technique. This is a bidirectional packet protocol, which can send and receive files at the same time. It requires a full-duplex connection and an 8-bit clean data path. It is currently understood by Taylor UUCP only. t This protocol is intended for use over a TCP connection or other truly error-free networks. It uses packets of 1,024 bytes and requires an 8-bit clean connection. e This should basically do the same as t. The main difference is that e is a streaming protocol and is thus suited only to reliable network connections. f This is intended for use with reliable X.25 connections. It is a streaming protocol and expects a 7-bit data path. 8-bit characters are quoted, which can make it very inefficient. G This is the System V Release 4 version of the g protocol. It is also understood by some other versions of UUCP. a This protocol is similiar to ZMODEM. It requires an 8-bit connection, but quotes certain control characters like XON and XOFF. Tuning the Transmission Protocol All protocols allow for some variation in packet sizes, timeouts, etc. Usually, the defaults work well under standard circumstances, but may not be optimal for your situation. The g protocol, for instance, uses window sizes from 1 to 7, and packet sizes in powers of 2 ranging from 64 through 4096. If your telephone line is usually so noisy that it drops more than 5 percent of all packets, you should probably lower the packet size and shrink the window. On the other hand, on very good telephone lines the protocol overhead of sending acknowledgments for every 128 bytes may prove wasteful, so you might increase the packet size to 512 or even 1,024. Most binaries included in Linux distributions default to a window size of 7 and 128-byte packets. Taylor UUCP lets you tune parameters with the protocol-parameter command in the sys file. For instance, to set the g protocol’s packet size to 512 when talking to pablo, you have to add: system pablo … protocol-parameter g packet-size 512 The tunable parameters and their names vary from protocol to protocol. For a complete list of them, refer to the documentation enclosed in the Taylor UUCP source. Selecting Specific Protocols Not every implementation of uucico speaks and understands each protocol, so during the initial handshake phase, both processes have to agree on a common one. The master uucico offers the slave a list of supported protocols by sending Pprotlist, from which the slave may pick one.