Cisco UBR904 Troubleshooting Guide - Page 43

show controllers cable-modem mac Table 8 Show Controllers Cable-Modem MAC State Field Descriptions (Continued) Field Burst Descriptor: Interval Usage Code Modulation Type Differential Encoding Preamble Length FEC Error Correction FEC Codeword Info Bytes Scrambler Seed Maximum Burst Size Guard Time Size Last Codeword Length Scrambler on/off Network Access Vendor ID Auth. Wait Timeout Reauth. Wait Timeout Auth. Grace Time Op. Wait Timeout Retry Wait Timeout Description A compound type/length/value (TLV) encoding that defines, for each type of upstream usage interval, the physical-layer characteristics that are to be used during that interval. Each burst descriptor is given an identifying number. Each upstream transmit burst belongs to a class which is given a number called the IUC (interval usage code). Bandwidth maps messages (MAP) are used by IUC codes to allocate upstream time slots. The following types are currently defined: 1. Request: bandwidth request slot 2. Request/Data: bandwidth request or data slot 3. Initial Maintenance: initial link registration contention slot 4. Station Maintenance: link keep-alive slot 5. Short Data Grant: short data burst slot 6. Long Data Grant: long data burst slot Upstream modulation format. (1 = QPSK; 2 = 16QAM) Indicates whether or not differential encoding is used. (1 = yes; 2 = no) Length of the preamble in bits. The value must be an integral number of symbols-a multiple of 2 for QPSK; a multiple of 4 for 16QAM. Length of the forward error correction in bytes. The range is 0-10 bytes; a value of 0 implies no forward error correction. Number of information bytes in the FEC codeword. 15-bit seed value loaded at the beginning of each burst after the register has been cleared. Not used if scrambler is off. Maximum number of mini-slots that can be transmitted during this burst type. When the interval type is Short Data Grant, this value must be greater than 0. If this value is 0, the burst size is limited elsewhere. Amount of time in symbols between the center of the last symbol of one burst and the center of the first symbol of the preamble of an immediately following burst in an upstream transmission from the cable modem to the CMTS. Indicates whether or not the length of the last codeword is fixed or shortened. (1 = fixed; 2 = shortened) Indicates whether or not a scrambler is enabled in the upstream modulator. (1 = on; 2 = off) Indicates whether or not the cable modem has access to the HFC network. Unique identifier specifying the cable modem manufacturer. The number of seconds the cable modem waits for a reply after sending the Authorization Request message to the CMTS. The number of seconds the cable modem waits for a reply after it has sent an Authorization Request message to the CMTS in response to a reauthorization request or an Authorization Invalid message from the CMTS. The number of seconds before the current authorization is set to expire that the grace timer begins, signaling the cable modem to begin the reauthorization process. The number of seconds the TEK state machine waits for a reply from the CMTS after sending its initial Key Request for its SID's keying material. The number of seconds the TEK state machine waits for a replacement key for this SID after the TEK grace timer has expired and the request for a replacement key has been made. Troubleshooting Tips for the Cisco uBR904 Cable Modem 43