Escon Channel Throughput
Although the 100baseT LAN can operate with 3–5 MBps throughput range on a heavily loaded system, the Escon channel specified at 17 MBps can reach very close to its maximum specified throughput. Tests done with Host Integration Server on a channel-attached quad PP200 were able to reach 12 MBps against a large mainframe using LU 6.2 doing straight memory-to-memory transfer. This rate is not typically reached except during system backup procedures or database distribution.
To place this result in the right context for a large online transaction processing (OLTP) system doing 500 TPS with transactions typically consisting of 200-byte input and 1900-byte reply, the Escon overall data rate would be 1 MBps plus some overhead. The Escon channel rarely becomes the system bottleneck because one adapter can support multiple 17-MBps channels using the Escon Multiple Image Facility (EMIF).