dsx1 Frac Table

1.3.6.1.2.1.10.18.13

This table is deprecated in favour of using ifStackTable. The table was mandatory for systems dividing a DS1 into channels containing different data streams that are of local interest. Systems which are indifferent to data content, such as CSUs, need not implement it. The DS1 fractional table identifies which DS1 channels associated with a CSU are being used to support a logical interface, i.e., an entry in the interfaces table from the Internet-standard MIB. For example, consider an application managing a North American ISDN Primary Rate link whose division is a 384 kbit/s H1 _B_ Channel for Video, a second H1 for data to a primary routing peer, and 12 64 kbit/s H0 _B_ Channels. Consider that some subset of the H0 channels are used for voice and the remainder are available for dynamic data calls. We count a total of 14 interfaces multiplexed onto the DS1 interface. Six DS1 channels (for the sake of the example, channels 1..6) are used for Video, six more (7..11 and 13) are used for data, and the remaining 12 are are in channels 12 and 14..24. Let us further imagine that ifIndex 2 is of type DS1 and refers to the DS1 interface, and that the interfaces layered onto it are numbered 3..16. We might describe the allocation of channels, in the dsx1FracTable, as follows: dsx1FracIfIndex.2. 1 = 3 dsx1FracIfIndex.2.13 = 4 dsx1FracIfIndex.2. 2 = 3 dsx1FracIfIndex.2.14 = 6 dsx1FracIfIndex.2. 3 = 3 dsx1FracIfIndex.2.15 = 7 dsx1FracIfIndex.2. 4 = 3 dsx1FracIfIndex.2.16 = 8 dsx1FracIfIndex.2. 5 = 3 dsx1FracIfIndex.2.17 = 9 dsx1FracIfIndex.2. 6 = 3 dsx1FracIfIndex.2.18 = 10 dsx1FracIfIndex.2. 7 = 4 dsx1FracIfIndex.2.19 = 11 dsx1FracIfIndex.2. 8 = 4 dsx1FracIfIndex.2.20 = 12 dsx1FracIfIndex.2. 9 = 4 dsx1FracIfIndex.2.21 = 13 dsx1FracIfIndex.2.10 = 4 dsx1FracIfIndex.2.22 = 14 dsx1FracIfIndex.2.11 = 4 dsx1FracIfIndex.2.23 = 15 dsx1FracIfIndex.2.12 = 5 dsx1FracIfIndex.2.24 = 16 For North American (DS1) interfaces, there are 24 legal channels, numbered 1 through 24. For G.704 interfaces, there are 31 legal channels, numbered 1 through 31. The channels (1..31) correspond directly to the equivalently numbered time-slots.