We describe a deterministic model of packet delay and use it to derive both the packet pair [2] p... more We describe a deterministic model of packet delay and use it to derive both the packet pair [2] property of FIFO-queueing networks and a new technique packet tailgating ) for actively measuring link bandwidths. Compared to previously known techniques, packet tailgating usually consumes less network bandwidth, does not rely on consistent behavior of routers handling ICMP packets, and does not rely on timely delivery of acknowledgments.
Byte stuffing is a process that transforms a sequence of data bytes that may contain 'illegal... more Byte stuffing is a process that transforms a sequence of data bytes that may contain 'illegal' or 'reserved' values into a potentially longer sequence that contains no occurrences of those values. The extra length is referred to in this paper as the overhead of the algorithm.To date, byte stuffing algorithms, such as those used by SLIP [RFC1055], PPP [RFC1662] and AX.25 [ARRL84], have been designed to incur low average overhead but have made little effort to minimize worst case overhead.Some increasingly popular network devices, however, care more about the worst case. For example, the transmission time for ISM-band packet radio transmitters is strictly limited by FCC regulation. To adhere to this regulation, the practice is to set the maximum packet size artificially low so that no packet, even after worst case overhead, can exceed the transmission time limit.This paper presents a new byte stuffing algorithm, called Consistent Overhead Byte Stuffing (COBS), that tig...
As organizations with high system availability requirements move to UNIX, the elimination of down... more As organizations with high system availability requirements move to UNIX, the elimination of down-time in the UNIX environment becomes a more important issue. Designing for fast recovery, rather than crash prevention, can provide low-cost highlyavailable systems without sacrificing performance or simplicity. In Sprite, a UNIX-like distributed operating system, we accomplish this fast recovery in part through the use of a recovery box: a stable area of memory in which the system stores carefully selected pieces of system state, and from which the system can be regenerated quickly. Error detection using checksums allows the system to revert to its traditional reboot sequence if the recovery box data is corrupted during system failure. Recent statistics about the types and frequencies of operating system failures indicate that fast recovery using the recovery box will be possible most of the time. Using our recovery box implementation, a Sprite file server recovers in 26 seconds and a ...
We describe a deterministic model of packet delay and use it to derive both the packet pair [2] p... more We describe a deterministic model of packet delay and use it to derive both the packet pair [2] property of FIFO-queueing networks and a new technique packet tailgating ) for actively measuring link bandwidths. Compared to previously known techniques, packet tailgating usually consumes less network bandwidth, does not rely on consistent behavior of routers handling ICMP packets, and does not rely on timely delivery of acknowledgments.
Byte stuffing is a process that transforms a sequence of data bytes that may contain 'illegal... more Byte stuffing is a process that transforms a sequence of data bytes that may contain 'illegal' or 'reserved' values into a potentially longer sequence that contains no occurrences of those values. The extra length is referred to in this paper as the overhead of the algorithm.To date, byte stuffing algorithms, such as those used by SLIP [RFC1055], PPP [RFC1662] and AX.25 [ARRL84], have been designed to incur low average overhead but have made little effort to minimize worst case overhead.Some increasingly popular network devices, however, care more about the worst case. For example, the transmission time for ISM-band packet radio transmitters is strictly limited by FCC regulation. To adhere to this regulation, the practice is to set the maximum packet size artificially low so that no packet, even after worst case overhead, can exceed the transmission time limit.This paper presents a new byte stuffing algorithm, called Consistent Overhead Byte Stuffing (COBS), that tig...
As organizations with high system availability requirements move to UNIX, the elimination of down... more As organizations with high system availability requirements move to UNIX, the elimination of down-time in the UNIX environment becomes a more important issue. Designing for fast recovery, rather than crash prevention, can provide low-cost highlyavailable systems without sacrificing performance or simplicity. In Sprite, a UNIX-like distributed operating system, we accomplish this fast recovery in part through the use of a recovery box: a stable area of memory in which the system stores carefully selected pieces of system state, and from which the system can be regenerated quickly. Error detection using checksums allows the system to revert to its traditional reboot sequence if the recovery box data is corrupted during system failure. Recent statistics about the types and frequencies of operating system failures indicate that fast recovery using the recovery box will be possible most of the time. Using our recovery box implementation, a Sprite file server recovers in 26 seconds and a ...
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Papers by Mary Baker