Split TCP

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Split TCP (also: TCP with proxies ) describes a concept for improving data transmission rates in mobile, wireless ad hoc networks .

Split TCP was further developed from the Transmission Control Protocol (TCP) at the University of California Riverside . It should reduce unnecessary effort when finding a new network route and reduce problems of the TCP with several connections of a node. In TCP, it is possible that the nodes do not divide the bandwidth equally between connections. If several connections go through a node, preference is given to the one that was established first, carries more data packets and has a shorter route to the source. If a further connection is to be established via the node that runs across the existing connections, it is possible that this is suppressed until fewer data packets are sent via the existing connections. This can reduce network performance. To solve this problem, different rules are prescribed in Split-TCP, according to which a proxy takes care of the forwarding of the IP packet after a certain number of hops (connection nodes in the ad-hoc network) .

The following rules are used:

  1. As with TCP, packets are forwarded via normal hops.
  2. A hop becomes a proxy when an IP packet has already passed through a certain number of hops.
  3. A proxy is only proxy for one connection; for other connections it also serves as a hop.
  4. A proxy sends a local acknowledgment ( LACK ) back to the previous source (proxy or hop).
  5. The proxy is then responsible for forwarding the data packet.
  6. The local confirmation (LACK) is only sent to the neighbor, no further.
  7. An acknowledgment ( ACK ) is sent back from the destination to the source in the same way .

Buffering rules:

  1. Data packets that have not yet been confirmed are saved for all connections.
  2. Acknowledgments ACK

The acknowledgment (ACK) from source to destination is an end-to-end control that is also used with conventional TCP.

In the first publication it was shown that the use of split TCP, depending on the load on the network and other factors, could increase the performance of the network by around 10 to 20 percent.

Individual evidence

  1. ↑ Kopparty et al .: Split TCP for Mobile AdHoc Networks . (PDF; 78 kB)