ZEC Adding RIST Outputs

The RIST output can be push streams or have them pulled to/from a RIST-enabled device. RIST seeks to provide reliable, high performance media transport by using UDP at the transport layer to avoid the inefficiencies of TCP, then layering on top Forward Error Correction and Retransmits to add the reliability inherently absent from UDP.

Zixi supports the following RIST profiles:

Simple Profile (PUSH only) - The RIST Simple Profile provides best-in-class packet protection, as well as support for multi-link bonding and seamless switching.
Main Profile (PUSH/PULL) – The RIST Main Profile builds upon the features of the Simple Profile to provide backwards compatibility, while opening the door for additional features, including:
- Encryption and authentication - RIST Main Profile uses industry-standard DTLS or PSK with a variety of available cyphers to ensure the most up-to-date protection, while being flexible to accommodate local legal regulations. Support for pre-shared keys is also included, which makes RIST Main Profile compatible with one-to-many environments such as satellite or multicast distribution.
- Native tunneling and multiplexing - the ability to combine multiple Simple Profile RIST streams into one single connection, optionally with one single encryption and authentication step, using industry-standard GRE over UDP.
- Bandwidth optimization - by deleting NULL packets at the source and re-inserting them at the destination.
- Support for high bit rate streams - The RIST Main Profile includes an RTP header extension which increases the sequence number size to 32-bits, and therefore increases the maximum size of retransmission buffers, and thus opens the door for higher bitrate streams, such as lightly compressed (e.g. JPEG 2000, Tico) and uncompressed video.

Contact your Zixi representative to learn more about interoperability testing between ZEC and 3rd party devices. More details about RIST can be found at www.rist.tv

To Create a RIST Output:

In the ZEC Outputs page, click . The New output window is displayed.
Select the RIST option (radio button).
Type in the unique identifier for this output in the Output Name.
Select an Input Stream to be made available on this output from the drop-down list.
Select the Show in Matrix check box to display this stream in the Matrix (see ZEC Using the Matrix). Default: Selected.
Specify the Output parameters (see Output Stream Parameters Table).
If you want to specify Billing Codes to identify and differentiate traffic on a ZEC for billing purposes, select this checkbox (see Output Stream Parameter Table below).
If you want to remux the stream to CBR (used for professional IRDs) in order to avoid bandwidth waste or add NULL packets and adjust the stream clock (PCR) in order to make the stream CBR, select Remultiplex/Pad and configure the respective parameters (see Output Stream Parameters Table).
You can decrypt an encrypted stream as it enters the ZEC. To decrypt a stream, select the Decrypt Stream checkbox and fill in the parameters as describes in the Output Stream Parameter Table below. For more information, see Decrypting an Output Stream in ZEC.
Click OK.
The new RIST Output with its settings is created and now appears on the Outputs screen.

Output Stream Parameters Table

Parameter	Description
Output Parameters
Profile	Select one of the following RIST profiles that matches the input stream: Simple Profile (default) Main Profile
Type (Main Profile)	Select the stream direction: Push Pull
Host	Specify the destination IP address or URL of the host to which the steam will be pushed.
Port	Specify the target UDP port.
TTL	Specify the time-to-live (TTL). Used mainly to limit the range (or “scope”) of a multicast transmission. Leaving it as blank uses the default value specified by the operating system.
Smoothing [mms]	Enables transmission of the output at the correct rate. Required when the receiving device is sensitive and can’t lock on to the stream (in such a case, the recommended latency is 100 - 1000 ms).
SMPTE-2022 FEC	In the SMPTE-2022 FEC standard, 1-D and 2-D parity codes are systematic FEC codes of decent complexity that provide protection against bursty or random losses. This setting can be modified without interrupting an existing stream. To enable SMPTE-2022 FEC (Forward Error Correction) select one of the following parity options from the drop-down menu: 1D - SMPTE-2022 1D can fix a problem in ONE packet per row. This means that the number of rows specified should consider the packet loss rate- the shorter the row, the more error resilience can be achieved on the expense of bitrate level. However, longer rows increase the delay that the FEC will add. It is recommended to select this option when the packet loss is sporadic. The stream will occupy the source port and two ports above it (e.g. if the source port is 8988, it will occupy 8990). 2D - SMPTE-2022 2D uses a table of packets, which includes rows and columns. This option is more error resilient, but it increases the delay by (rowcolumn) packets and increases the bitrate with R+C packets per each table of RC packets. It is recommended to select this option when packet loss is bursty. The stream will occupy four ports above (e.g. if the source port is 8988, it will occupy 8992).
Bind to IP	Select from the drop-down list the local IP address to be used for this Input, OR select Any to enable any IP to be used.
Local Port	Specify from which local port to source the stream, if desired (instead of randomly chosen by the operating system).
Billing Codes	Billing codes are used to identify and differentiate traffic on a ZEC for billing purposes. When a billing code is added to a Source or Target, ZEC can track the traffic on that ZEC input or output separately from other inputs and outputs on the same ZEC. Billing codes are created by ZEC personnel on the ZEC Customer Portal for a particular organization.
Billing Code	Enter the billing code that corresponds to this stream. The relevant billing can be obtained from the organization that received the billing code from Zixi.
Billing password	Enter the password that corresponds to this billing code.
*RIST main profile parameters*
Use DTLS	Select this checkbox to encrypt the stream dynamically using DTLS.
*Remultiplex/Pad*	Select this checkbox to enable remuxing from VBR MPEG-TS to MPEG-TS CBR (used for professional IRDs) or padding with null packets.
Mode	Select one of the following: Pad – adds NULL packets and adjusts the stream clock (PCR) in order to make the stream CBR. Remultiplex - performs demux->mux and rebuilds the stream according to the below parameters.
Target bitrate [kbps]:	Specify the CBR bitrate to target for a remuxed stream.
Buffer Size [ms]	Specify the size of the buffer that will be used for the remixing. A larger buffer increases the quality, but also increases latency.
No NULL Packets	Select this option to re-multiplex the stream to CBR but remove the NULL packets in order to maintain low bitrate.
Enable Decryption	Select this checkbox to decrypt an encrypted stream.
Decryption type	If the stream has been encrypted, you can decrypt through the output by selecting this checkbox and specifying the type of ecryption that was used. Select Automatic to decrypt a stream that has been encrypted using Automatic encryption. Only if the stream has not been encrypted, select None (default). Important Notice: if the stream has been encrypted you must decrypt it in the output.
Decryption key	If the decryption type includes a key, enter the key to decrypt the stream during output.
Enable IFB/Talkback	Select this checkbox to enable IFB/Talkback for one-way communication from the director or assistant director to on-air talent or a remote location. Selecting the checkbox allows the decoder with a ZEC to send audio back to the encoder with a Zixi Feeder. This offers the ability to, for example, give audio feedback to the camera operator.
Port	The port that will be used to send the audio feedback.