Specifications

A-3
Cisco ONS 15530 Planning Guide
OL-7708-01
Appendix A IBM Storage Protocol Support
Supported Protocols
Figure A-2 ESCON Data Rate as a Function of Distance
FICON
FICON (Fiber Connection) is the next generation bidirectional channel protocol used to connect
mainframes directly with control units or ESCON aggregation switches (ESCON Directors with a bridge
card). FICON runs over Fibre Channel at a data rate of 1.062 Gbps. One of the main advantages of
FICON is the lack of performance degradation over distance that is seen with ESCON. FICON can reach
a distance of 100 km before experiencing any significant drop in data throughput.
Coupling Facility
Coupling Facility (CF) links, also known as ISC (InterSystem Channel) links, are used to connect
mainframes to a CF. The CF is used by multiple mainframes to share data in a sysplex or Parallel Sysplex
environment. This data sharing capability is key to the high availability features of a GDPS. Coupling
links run over Fibre Channel at data rates of 1.0625 Gbps (called ISC1 or ISC compatibility) and
2.1 Gbps (called ISC peer).
Sysplex Timer
Sysplex Timer links are the links used to provide the clock synchronization between the mainframes in
a Parallel Sysplex. There are two types of links used. The first is the link between each mainframe and
the Sysplex Timer, known as the ETR (external throughout rate) links. The second is the link between
redundant Sysplex Timers, referred to as the CLO (control link oscillator) links. In a high availability
GDPS environment, redundant Sysplex Timers are connected to each mainframe over ETR links, while
the timers are connected to each other over the CLO links. This protocol operates at 16 Mbps.
Data Rate
MB/sec
20
17.6
10
3.4
9
8.5 9 23 60
km
Distance
58985