Cisco Systems UBR924 manual Us Id

show controllers cable-modem mac

Table 8	Show Controllers Cable-Modem MAC State Field Descriptions (continued)
Field		Description
DS Symbol Rate		Downstream frequency in symbols per second.
DS QAM Mode		Downstream modulation scheme being used by the Cisco uBR924.
DS Search		Frequency bands scanned by the Cisco uBR924 when searching for a downstream
		channel. The Cisco uBR924’s default frequency bands correspond to the North
		American EIA CATV channel plan for 6 MHz channel slots between 90 MHz and
		858 MHz.
US ID		Identifier of the upstream channel to which this MAC management message refers.
		This identifier is arbitrarily chosen by the CMTS and is only unique within the
		MAC-sublayer domain.
US Frequency		Transmission frequency used by the Cisco uBR924 in the upstream direction.
US Power Level		Transmit power level of the Cisco uBR924 in the upstream direction.
US Symbol Rate		Upstream frequency in symbols per second.
Ranging Offset		Delay correction (in increments of 6.25 µs/64) applied by the Cisco uBR924 to the
		CMTS upstream frame time derived at the Cisco uBR924. Used to synchronize the
		upstream transmissions in the time division multiple access (TDMA) scheme, this
		value is roughly equal to the round-trip delay of the Cisco uBR924 from the CMTS.
Mini-Slot Size		Size T of the mini-slot for this upstream channel in units of the timebase tick of
		6.25 µs. Allowable values are 2, 4, 8, 16, 32, 64, or 128.
Change Count		Incremented by 1 by the CMTS whenever any of the values of this channel descriptor
		change. If the value of this count in a sebsequent upstream channel descriptor (UCD)
		remains the same, the Cisco uBR924 can quickly decide that the remaining fields
		have not changed, and may be able to disregard the remainder of the message.
Preamble Pattern		Byte pattern used for the preamble.
Burst Descriptor:		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.
Interval Usage Code		Each upstream transmit burst belongs to a class which is given a number called the
		IUC (interval usage code). Bandwidth MAP messages 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
Modulation Type		Upstream modulation format. (1 = QPSK; 2 = 16QAM)
Differential Encoding		Indicates whether or not differential encoding is used. (1 = yes; 2 = no)
Preamble Length		Length of the preamble in bits. This value must be an integral number of symbols—a
		multiple of 2 for QPSK; a multiple of 4 for 16QAM.
FEC Error Correction		Length of the forward error correction in bytes. The range is 0-10 bytes; a value of 0
		implies no forward error correction.
FEC Codeword Info Bytes		Number of information bytes in the FEC codeword.
Scrambler Seed		15-bit seed value loaded at the beginning of each burst after the register has been
		cleared. Not used if scrambler is off.

50Cisco IOS Release 12.0(5)T