• Speed of the network or transmission media Performance improves with a faster transmission medium. For example, the following are some typical raw data transfer rates:

  Channel-to-channel (fiber optics)

  4.0 MB/s

  16 Mbps LAN

  2.0 MB/s

  Channel-to-channel (regular)

  1.0 MB/s

  4 Mbps LAN

  0.5 MB/s

  High speed T1 carrier (1.544 Mbps)

  0.193 MB/s

  Fast remote 56 Kbps phone line

  0.007 MB/s

  19.6 Kbps modem

  0.002 MB/s

  9600 bps modem

  0.001 MB/s

  The data transfer rate is limited by the slowest transmission medium in the path to the host or System i™ database server.

• Network adapter or communication controller

  You should carefully plan the memory usage of the network adapter and communication controller. In addition, you should work with a network specialist to ensure that the controller has the capability to handle the extra traffic generated by DB2 Connect™.

• Network topology

  If data crosses from LAN to LAN, and from one network to another network, consider the travel time. Bridges, routers, and gateways will add to the elapsed time. For example, reducing the number of bridges that are crossed reduces the number of hops required for each request.

  The physical distance between nodes should also be considered. Even if a message is transferred by satellite, the transfer time is limited by the speed of light (3 * 10**8 m/s) and the round-trip distance between the sender and receiver.

• Network traffic

  If the bandwidth of the network has been fully utilized, both the response time and the data transfer rate for a single application will decrease.

  Congestion can occur in the network when data accumulates at a particular part of the network; for example, at an old NCP with a very small buffer size.

• Network reliability

  If the error rate of the network is high, the throughput of the network will decrease and this will cause poor performance because of data re-transmission.

Parent topic: DB2 Connect tuning