1. Ralph Lange: CA Gateway Update CA Gateway Update Ralph Lange – EPICS Collaboration Meeting March 2008 @ SSRF

2. Ralph Lange: CA Gateway Update Credits: Main Authors and Contributors Channel Access Development Jeff Hill (LANL) CA Gateway Development 1996Jim Kowalkowski (APS) Janet Anderson (APS) 1999Ken Evans (APS) 2000Ralph Lange (BESSY) 2002Ken Evans (APS) Jeff Hill (LANL) 2007Gasper Jansa (cosylab) Dirk Zimoch (SLS)

3. Ralph Lange: CA Gateway Update What is a CA Gateway? An application that forwards connections between CA clients and servers.

4. Ralph Lange: CA Gateway Update It's a Gateway. Allows CA between networks – configurable through regular expression filters and CA access security. Gateway CA Clients CA Servers (IOCs)

5. Ralph Lange: CA Gateway Update It‘s a Proxy. Clients point to one proxy that distributes the data with minimal impact on the IOCs. CA Clients CA Servers (IOCs) Gateway

6. Ralph Lange: CA Gateway Update Overview: Key Features As well CA server as CA client Usually runs on workstation with multiple network interfaces Connects and separates networks in terms of CA connections May use channel aliases (e.g. add prefixes) May cache data (CA get is answered by the gateway) Keeps IOC-side connections alive Watchdog mode restarts on core dump Provides statistics channels to allow monitoring

7. Ralph Lange: CA Gateway Update CA Gateway Configuration: Symmetric Each network sees the channels of all other networks. Gateways may run on a single host with multiple (virtual) interfaces.

8. Ralph Lange: CA Gateway Update CA Gateway Configuration: Reverse Gateway All networks see channels in network Z. The reverse Gateway forwards Gateway statistics.

9. Ralph Lange: CA Gateway Update CA Gateway Configuration: Alias Gateway The Gateway provides aliases for channel names.

10. Ralph Lange: CA Gateway Update Recent CA Gateway Changes Option to disable cache (forward each CA get to the IOC) Transparently works for Alarm Handler and Archiver connections Option to use Perl regexp instead of GNU regexp (allows easy negation of regexp) Numerous bugfixes (beacons missing, Gateway hangs) The CA Gateway is available from the EPICS extensions page.