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Allegro Multimeter Manual

SRT module

This module shows the traffic and quality metrics for the SRT (Secure Reliable Transport) protocol. SRT is a protocol for low-latency video transport via UDP, offering packet loss detection, retransmissions and native support for payload encryption.

The module supports media streams from ‘caller’ to ‘listener’ and ‘listener’ to ‘caller’. Currently, multiple streams per direction and SRT connection are not supported.

In SRT terms, the “caller” refers to the client and the “listener” refers to the server.

Overview

Section titled “Overview”

The ‘Overview’ tab shows the global SRT traffic and quality metrics.

IPs

Section titled “IPs”

The ‘IPs’ tab displays a table showing all the IP addresses on which SRT traffic has been detected.

  • IP: IP address

  • Alternativ names: Hostnames seen on the IP address.

  • Go to: A link to the SRT connections table for this IP address.

  • First packet time: The first time SRT traffic has been detected for this IP address.

  • Last packet time: The last time SRT traffic was detected for this IP address.

  • Data packets: Counts the number of SRT data packet per direction. The number of SRT control packets are not accounted for IP addresses.

  • Data packets/s: The number of SRT data packets per second and direction.

  • Lost Packets: The number of not seen SRT data packets per direction based on the sequence number tracking.

  • Out of order packets: The number of out-of-order SRT data packets per direction based on the sequence number tracking.

  • Retransmitted packets: The number of retransmitted SRT data packets per direction based on the retransmissions flag in the packet header.

  • Retransmitted packets ratio: The ratio of retransmitted SRT data packets to seen SRT data packets.

  • Packet time delta (max): The maximum packet time delta of the SRT data packets per direction.

  • Jitter: The maximum jitter of the SRT data packets per direction.

Connections

Section titled “Connections”

The connections page shows a table with all SRT connections of a IP address.

  • Caller: IP address, port and seen hostnames of the caller.

  • Listener IP address, port and seen hostnames of the listener.

  • Go to A link to the connections details page.

  • Start time The start time of the connection.

  • Last activity: The last time there was activity on these connections.

  • Duration: Durration of the connection.

  • Packets: The number of SRT packets per direction.

  • Bytes: The number of SRT bytes per direction.

  • Packets/s: The number of SRT packets per second and direction.

  • Bytes/s: The number of SRT bytes per second and direction.

  • Lost Packets: The number of not seen SRT data packets per direction based on the sequence number tracking.

  • Out of order packets: The number of out-of-order SRT data packets per direction based on the sequence number tracking.

  • Retransmitted packets: The number of retransmitted SRT data packets per direction based on the retransmissions flag in the packet header.

  • Payload: Seen SRT data payload per direction:

    • none: No SRT data packets.
    • encrypted: SRT data packets with encrypted payload.
    • unencrypted: SRT data packets with unencrypted payload.

  • Packet time delta (max): The maximum packet time delta of the SRT data packets per direction.

  • Jitter: The maximum jitter of the SRT data packets per direction.