SRT Stream Settings

The following sections list the TS over SRT-specific parameters:

Connection

Setting	Default	Description/Values
Mode	Listener	Specifies the SRT Connection Mode (to simplify firewall traversal): Caller: The decoder acts like an SRT caller and connects to a server listening and waiting for an incoming call. Listener: The decoder acts like an SRT listener and listens for a server to connect to it. Rendezvous: Allows calling and listening at the same time. To simplify firewall traversal, Rendezvous Mode allows the encoder and decoder to traverse a firewall without the need for IT to open a port.
Address	n/a	(Caller and Rendezvous Connection modes) Specifies the destination IP address for the SRT stream.
Source Port	Auto-Assign	(Caller Connection mode) Specifies the UDP source port for the SRT stream. If not filled in, a (default) source port will be assigned. Note This simplifies firewall configuration as the firewall/NAT rules can be precisely tailored to the SRT stream.
Destination Port	n/a	(Caller and Rendezvous Connection modes) Specifies the UDP destination port for the SRT stream.
Port	n/a	(Listener Connection mode only) Specifies the UDP local port for the SRT stream.

SRT Settings

SRT Settings

Setting	Default	Description/Values
Latency	20	Specifies how long the decoder will buffer received packets. Range = 20 - 8000 ms Note The SRT buffer, configured as “Latency’”, is the time reserved in the decoder to recover missing packets. Because real-time video cannot be paused, restarted, slowed down, or accelerated, the buffer adds a fixed delay in the end-to-end latency. If a lost packet cannot be recovered, this may result in an A/V artifact. In this case, you should increase the SRT latency as it is likely too low. Please see the SRT Deployment Guide for tuning guidance.
Encrypted	Off	Toggle to On to enable decryption of encrypted streams.
Passphrase	n/a	(Encrypted must be On; must match encoder passphrase) This parameter is required if the stream is encrypted and is used to retrieve the cryptographic key protecting the stream. Range = 10-79 UTF8 characters
Reject Unencrypted Callers	On	(Listener Connection mode only, and Encrypted must be On) For security reasons, when encryption is enabled in the decoder's SRT Listener stream configuration, this option causes the decoder to reject all unencrypted SRT Caller streams.

SRT to UDP Stream Conversion

Setting	Default	Description/Values
Enable	Disabled	Check this checkbox to enable UDP retransmission of SRT streams on the local network. Note The SRT input stream may be encrypted and includes error correction. Enable this to rebroadcast the SRT stream on the local LAN without the encryption and error correction elements over UDP. A single multicast or unicast destination TS/UDP stream is supported for re-streaming.
Destination IP Address	n/a	Specifies the destination IP address for the stream.
Destination Port	n/a	Specifies the UDP source port for the stream.
TTL	64	(Time-to Live for stream packets) Specifies the number of router hops that IP packets from this stream are allowed to traverse before being discarded. Range = `1..255`
ToS	184 or 0xB8	(Type of Service) Specifies the desired quality of service (QoS). This value will be assigned to the Type of Service field of the IP Header for the outgoing streams. Range = `0..255` (decimal) or `0x00..0xFF` (hex) Important A DiffServ or DSCP (Differentiated Services Code Point) value must be converted to a ToS precedence value. For example, AF41 or DSCP 34 becomes ToS 136. For more information, see RFC2474. Note The ToS setting must be chosen so as to not interfere with Voice over IP systems and other equipment that may reside on your network. For example, when the ToS value for a stream is set to 0xB8, it can interfere with some third party Voice / IP Telephony systems.