gsm Cs V42bis Maximum Codewords

This attribute specifies the maximum number of V.42bis codewords the IWF supports. A codeword is a binary number that represents a string of characters in compressed form. V.42bis keeps a dictionary of codewords for each compression direction. During Exchange Identification (XID) negotiation of parameter P1 (number of codewords), both sides (IWF and mobile or IWF and Public Switched Telephone Network (PSTN)) agree on the total number of codewords in the dictionaries. Changes to this attribute impact the compression ratio for the encoder (component GsmV42BisOp attribute compRatioEncoder). Changes also impact the amount of memory used (more memory is used when increasing the attribute). The gain in performance obtained from the selection of a larger dictionary may be offset by the larger codeword size needed, and for certain types of data, better performance may be obtained by using a smaller dictionary. The negotiated value can be viewed in the component GsmIwfV42bisOp attribute maximumCodewords . Changes to this attribute do not effect existing calls.