![SIL-SA_Master_Agent_Graphic_081017](https://i0.wp.com/www.yumaworks.com/wp-content/uploads/SIL-SA_Master_Agent_Graphic_081017.png?fit=705%2C372&ssl=1)
Asynchronous Distributed Transactions:
Server instrumentation code can run in the main server or in multiple sub-agents. SIL-SA and YControl libraries link with your process and handle all communication and transaction management with the main server.
The difference between SIL & SIL-SA is that SILs are synchronously connected to the server in the same process and the SIL-SAs are asynchronously connected to the server so that they can instrument different processes such as line cards in a chassis based device. There are many server APIs that are only available to the SIL libraries.
For more information on SIL-SA, refer to our Knowledge Base: