An Investigation into Transport Protocols and Data Transport ...

10.2. New-TCP Suitability Study 250
local site traffic. As such, the overhead and friendliness becomes much more
important under such scenarios.
As the logical latencies between Tier-1 to Tier-2 and Tier-2 to Tier-3/4
are likely to be small due the region design of the MONARC system, the
issues of H-TCP having higher overheads at very long latencies becomes less
of an issue.
However, there is a higher chance of insufficient network buffering due to
the traversal through many autonomous systems and the requirement for the
LHC traffic to share with normal site traffic. Also should many LHC flows
be sharing the infra-structural links, the requirement for FAST to maintain
a queue size proportional to the number of connections makes provision of
such buffers difficult.
Due to the unfriendliness and RTT unfairness constraints of ScalableTCP,
BicTCP and HSTCP, it is not recommended for use in this application area.
10.2.3 Area 3
Dedicated circuit usage in this application area only requires that the single
New-TCP flow maintains high throughput. Under such scenario’s, BicTCP,
ScalableTCP and FAST are able to achieve very high utilisation of the network
pipes.
Due to the loss-based nature of BicTCP and ScalableTCP, FAST is able
to maintain a lower overhead, which may give it the advantage in being able
to sustain higher throughputs. However, this is only the case when there are
sufficiently sized buffers available on the network path. Depending on the
type of dedicated circuit (e.g. and entire SONET link, or DiffServ/MPLS
provisioned) and more importantly who it is leased from, it may or may not