The following parameters are defined when you create a new audio device or a new stream sender.

To make Lawo VSC easy to configure, most of the parameters are hidden from view unless you select Custom (in the Configuration field) to reveal the advanced parameters.

The parameters can also be viewed from HOME if HOME integration is configured.

The "Label", "Media Interface" and "Protection" fields cannot be modified once a stream is created.

LabelLink to Label

The Sender Label identifies the stream to other network users. It cannot be left blank and cannot be edited once you have created the stream.

The identifier string must not contain the character “/” (ASCII/UTF-8: 47) and must begin with a letter or the lower line character “a”-“z”, “A”-“Z”, “_” (ASCII/UTF-8: 65-90, 97-122 ,95).

Sender labels must not exceed 28 characters.

Media Interface & ProtectionLink to Media Interface & Protection

These fields determine which interface, or interfaces, will be used to transmit the stream to the network.

To create SMPTE ST2022-7 compatible streams, the "Protection" field must be set to Dual Redundant to activate both interfaces. If redundant streaming is not required, then you can choose to issue the stream from either the Primary or Secondary interface.

ChannelsLink to Channels

This value sets the number of audio channels to be encoded.

Sample RateLink to Sample Rate

This field is for information only. It describes the sample rate (fs).

Frame Size (Packet Time)Link to Frame Size (Packet Time)

The frame size sets the number of samples per channel per network packet, and defines the packet time (in seconds). The default value = 6 samples (equivalent to 125 µs when the sample rate is 48kHz).

The smaller the value, the more often the device transmits packets. This results in a lower sending latency, but also a higher demand on the network's bandwidth. In Lawo devices, the frame size limits the number of senders that can be created by each device.

CodecLink to Codec

This field selects the encoding method used for the digital audio. There are three possible options. The default value = L24.

  • L16 = 16-bit Linear PCM
  • L24 = 24-bit Linear PCM
  • AM824 = 24-bit Linear PCM + 8-bit metadata, a non-standard format commonly used in AES/EBU.

TTL (Time to Live)Link to TTL (Time to Live)

The TTL value can be used to prevent data packets from circulating indefinitely. The default value = 16.

You may need to increase the TTL value if your network includes several Layer 3 network switches (Gateways).

RTP Payload TypeLink to RTP Payload Type

This field describes the format of the transported content. The default value = 98.

Primary / Secondary Multicast Address & Destination UDP PortLink to Primary / Secondary Multicast Address & Destination UDP Port

These fields show the multicast IP addresses and UDP port assigned to the stream. By default, when you create a new stream, the multicast addresses are assigned automatically and the UDP port value is set to 5004.

If you wish to assign a multicast IP address and port manually, then type the required values into the corresponding fields.

Primary / Secondary Source AddressLink to Primary / Secondary Source Address

These fields are for information only. They show the IP address of the multicast address provider (used in auto mode).