Your EDnet supplied CDQ2000 is compatible with several Layer II audio codecs, a feature that brings with it a certain degree of complexity in configuration. The purpose of this document is to provide clear and concise instructions for the configuration of both your CDQ2000 and the most common compatible codecs you may run into.

1. General Compatibility Issues

Regardless of what kind of codec you're connecting to, there are some common issues that need to be addressed, preferably before the session takes place. As most common codecs offer several mono and stereo modes, both sites should be aware of what mode will be used for the session. With your codec, the sending and receiving modes can be different - one side can transmit in mono while receiving in stereo.

The second important issue common to all codec types is the data speed used by the codec. In the US, ISDN lines are commonly used for both 56k and 64k calls. Prior to ISDN being widely available the common data service was 56k, and that rate is still the most widely used as it's guaranteed to work to all locations. Using a 64k data rate will give you slightly higher transmission quality in stereo, however, and you may find some sites that use 64k primarily. Layer II codecs such as your CDQ2000 usually combine two 56k or 64k calls to provide full audio bandwidth, so you may find some studios who say their rate is 112k (2 * 56) or 128k (2 * 64).

As of this writing, all EDnet sites except for Suite Sync in Mexico City, and most non-EDnet sites in the US are set at 56k per data channel, or 112k on the CDQ. (Changing the data rate requires reconfiguration of both your terminal adapter and your CDQ. Contact EDnet for instructions on reconfiguring your specific terminal adapter. If you have Switched56 service (you'll have two separate dialers in this case) you're limited to 56k per channel and the other side will also have to be set to 56k.)

2. Compatibility With Non-EDnet Codecs

Make sure to verify what bit rate is to be used prior to the session. If you're unable to find out in advance, try 56k first unless it's an international site, in which case try 64k first.

The following outlines the steps necessary based on the most common configurations of the codecs specified. If you are unsuccessful after following these instructions, contact EDnet at +1 800 933-3638.

CCS CDQ2000 and CDQ Prima (EDnet MPEG/128 or Digital Patch) - For operation with EDnet CDQ sites, you need only select the appropriate audio mode (mono or stereo) and, if stereo, the type (joint stereo or dual mono). The best audio quality will always be achieved in mono mode. Do note, however, that due to the way the CDQ processes audio, only the left audio input should be fed while sending in mono to avoid artifacts.

If sending stereo program, the Joint Stereo mode will provide the highest fidelity and frequency response, but does not deliver two independent channels. It basically determines the difference between the audio on each channel during compression and avoids sending redundant data. If you need true discrete two channel audio, perhaps for timecode, use the Dual Mono mode. Please remember that Dual Mono provides only about a 9kHz frequency response. For a timecode session we recommend that the recording end send the timecode and talkback using Dual Mono while the sending studio transmits the audio in Mono or Joint Stereo modes to obtain the highest quality recording.

CCS CDQ2000/2001 (non-EDnet) - For use with non-EDnet CDQ2000/2001, if it's a send/receive unit or a receive only unit, one end may have to make a slight configuration change. No change is necessary on send only units. On the back of their unit are two rows of DIP switches (one row if receive only). On the lower row of DIP switches, switch 6 must be in the same position as on your unit. Yours will be up, however many non-EDnet sites leave this switch down. It doesn't matter who makes the change, but make sure it's up on your unit before doing a session with an EDnet site.

On the front of their CCS unit, the Line 1 and Line 2 Select switches should be down on both the Encoder and Decoder and the bit rate knob should be at 112k or 128k, depending on whether you are calling at 56k or 64k.

If they indicate that they have a BONDING only terminal adapter, such as an Adtran ISU-128 and are using their CDQ in single line mode, EDnet will have to bridge you.

CCS CDQ Prima - Non EDnet Prima sites may need to change one parameter in the Decoder section. From the front panel they should press the DEC menu button, select Indep , press ENTER, select YES, and press ENTER again. This corresponds to DIP switch 6 on the decoder side of your CDQ. If you prefer, you may turn switch 6 off instead of having the other side reconfigure their Prima. If you do this, make sure and return it to the up position before doing any sessions with EDnet sites.

They'll also need to be in CCS 2 Line mode at either 112k or 128k. (These options are set in the Encoder Line Fmt options and Encoder Bit Rate options.)

CCS CDQ 1000 - The CDQ1000 is a single line 56k or 64k codec offering both MPEG Layer II and G.722 compression. The two modes on the CDQ are selected via front panel switch. The CDQ1000 must be in Layer II or CCS mode and have the sampling rate set to 48kHz. On your end, set the bit rate knob on the CDQ to 56k or 64k, depending on the speed of the call* and flip the Line 1 Select switches on both encoder and decoder to the up position. Only one call is used for connection to a CDQ1000 and the frequency response is about 8kHz.

RE: - This unit should be compatible at 56k or 64k in single line mode. Set the bit rate knob on the CDQ to 56k or 64k, depending on the speed of the call* and flip the Line 1 Select switches on both encoder and decoder to the up position. Only one call is used for the connection and the frequency response is about 8kHz.

MPR LII Blue - This unit has been tested to be compatible in single line mode - follow the instructions for the RE: unit above. MPR indicates that their unit should be compatible in CCS 2 line mode at 112k or 128k, but we have been unable to verify this.

Telos Zephyr: - No configuration change is necessary from the standard EDnet setup on your end. The Zephyr should be set up for a 56k data rate, and a transmit mode of L2MONO128 for mono sessions or L2JSTEREO for stereo sessions. Regardless of mono/stereo mode, the Zephyr receive mode should be L2. Sessions with the Zephyr will be the same quality as sessions with another CDQ2000 or Prima.

Telos Zephyr (Mono): Some Zephyrs, known as mono units, are only capable of single line (56k or 64k) Layer 2 operation, limiting the audio frequency response to about 8kHz. (If the Zephyr is set to a stereo or Layer 2 Mono128 mode it will indicate that it lacks hardware support) To connect directly to a mono Zephyr, set the bit rate knob on the CDQ to 56k or 64k, depending on the speed of the call and flip the Line 1 Select switches on both encoder and decoder to the up position. Only one call is used for the connection. If you require higher fidelity, EDnet can bridge to mono Zephyr units using Layer 3 mode to provide 15kHz frequency response.

Note that some older Zephyrs do not have the Layer 2 option installed. If you encounter a site with only Layer 3 modes available to them, call EDnet for a bridge.

(64k operation requires reconfiguration of your terminal adapter as well as your CDQ. Contact EDnet for instructions on reconfiguring your specific terminal adapter. If you have Switched56 service (you'll have two separate dialers in this case) you're limited to 56k per channel and the other side will also have to be set to 56k.)

APT-X, DAS, DSM-100, 3D2, IDB System - These all refer to codecs using the apt-X algorithm, which are incompatible with the CCS. EDnet can bridge you to these sites.

Dolby AC-2, DolbyFax - These refer to Dolby's AC-2 codecs, which are incompatible with the CCS. EDnet can bridge you to these sites.