There are many factors that influence the speed at which stream switching occurs.  The following is a checklist of device settings and other configuration steps that will increase the switching speeds of your SVSI system.

Device Settings:

These are settings specific to encoders and decoders and must be applied to ALL devices in the system.

• All devices on the most recent version of firmware (1.8.8 minimum)
• Scaler should be enabled on all decoders and set to a specific output resolution and timing (no Auto settings)
• Last Frame Hold enabled on all decoders
• Local Play Holdoff set to 10 seconds 

Network:

Every network and network configuration is different, based on the needs of the organization or installation.  However, there are some basic rules that should be followed.

• Ensure that the Minimum Network Requirements Guide is followed, and all network devices are configured according to its specifications.
• Make sure all network devices have sufficient specs to be utilized in an AVOIP environment.

Handshakes:

Most latency is added in the various handshakes that occur between devices when a switch occurs.  This group of items is a list of handshakes and best practices to ensure the handshakes are as fast as possible.

• Both encoder sources should have the same refresh rate (Hz), any changes in timing between two encoders will increase switching times.
• Switching between devices that are HDCP and non-HDCP (or vice versa) will increase switch times.
• Any switching between devices that utilize different versions (1.4 vs 2.2) or types (1 vs 2) of HDCP will increase switch times.

A good check for any changes is if you receive a black frame while doing a switch, this will indicate one of the above handshakes is not a same-to-same comparison and one or more of these handshakes are coming into effect and increasing the switch time.  Utilization of different HDCP versions is something tricky that usually sneaks into a system that catch people unawares.  Please refer to all manufacturer’s documentation for each device in the signal path to guarantee all devices agree on their specifications.