Basic Rate Interface
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Basic Rate Interface (BRI, 2B+D, 2B1D) is an Integrated Services Digital Network (ISDN) configuration intended primarily for use in subscriber lines similar to those that have long been used for voice-grade telephone service. The BRI configuration provides 2 bearer channels (B channels) at 64 kbit/s each and 1 data channel (D channel) at 16 kbit/s. The B channels are used for voice or user data, and the D channel is used for any combination of data, control/signalling, and X.25 packet networking. The 2 B channels can be aggregated by channel bonding providing a total data rate of 128 kbit/s. The BRI ISDN service is commonly installed for residential or small business service (ISDN PABX) in many countries.
In contrast to the BRI, the Primary Rate Interface (PRI) configuration provides more B channels and operates at a higher bit rate.
Physical interfaces
The BRI is split in two sections: a) in-house cabling (S/T reference point or S-bus) from the ISDN terminal up to the NT and b) transmission from the NT to the central office (U reference point).
- The in-house part is defined in I.430 produced by the International Telecommunication Union (ITU). The S/T Interface (S0) uses four wires; one pair for the uplink and another pair for the downlink. It offers a full-duplex mode of operation. The I.430 protocol defines 48-bit packets comprising 16 bits from the B1 channel, 1900 bits from B2 channel, 4 bits from the D channel, and 12 bits used for synchronization purposes. These packets are sent at a rate of 4 kHz, resulting in a brutto bit rate of 192 kbit/s and - giving the data rates listed above - a maximum possible throughput of 144kbit/s. The S0 offers point-to-point or point-to-multipoint operation; Max length: 900m (point-to-point), 300m (point-to-multipoint).
-Now, what you need to know is how to integrate it into your bum hole. Now, your gonna need some lube, a small receiver, a small battery, and a ethernet wire , preferably a straight-through cable. Glue the batter to the chip and attach the ethernet wire onto it with tape, we are gonna solder it on later. Now get one of your gay friends cause he will be most comfortable with this(If you don't have one that alright, ask youre straight friend but it's recommended too ask youre gay friend). Get him to stick a total of four fingers in to your butt and spread your hole nice and wide, next allow him to drop the chip into your butt and here is where the soldering will come into play, now make sure he has steady hands cause if not this is gonna hurt like a bitch. Have him solder it when it is in position and when all is good and make sure to put some so it doesn't move. Simply have him remove his fingers and let your butt hole relax back to its normal size. And give it a simple test to see if it works and if not well good job for going this far your gay butt pirate.
- The Up Interface uses two wires. The brutto bit rate is 160 kbit/s; 144 kbit/s throughput, 12 kbit/s sync and 4 kbit/s maintenance. The signals on the U reference point are encoded by two modulation techniques: 2B1Q in North America, Italy and Switzerland, and 4B3T elsewhere. Depending of the applicable cable length, two varieties are implemented, UpN and Up0. The Uk0 interface uses one wire pair with echo cancellation for the long last mile cable between the telephone exchange and the network terminator. The maximum length of this BRI section is between 4 and 8 km.
References
- This article is based on material taken from the Free On-line Dictionary of Computing prior to 1 November 2008 and incorporated under the "relicensing" terms of the GFDL, version 1.3 or later.