Cisco Systems UBR900 specifications Us Id

show controllers cable-modem mac

Table 12	show controllers cable-modem MAC State Field Descriptions (continued)
Field		Description
DS Frequency		Downstream frequency acquired by the Cisco uBR900 series during its last
		initialization sequence.
DS Symbol Rate		Downstream frequency in symbols per second.
DS QAM Mode		Downstream modulation scheme being used by the Cisco uBR900 series.
DS Search		Frequency bands scanned by the Cisco uBR900 series when searching for a
		downstream channel. The Cisco uBR900 series’ 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 uBR900 series in the upstream direction.
US Power Level		Transmit power level of the Cisco uBR900 series 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 uBR900 series to
		the CMTS upstream frame time derived at the Cisco uBR900 series. 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 uBR900 series 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 uBR900 series 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.

100Cisco IOS Release 12.0(7)T