Zephyr Compatible Codecs

Need to connect your Telos Zephyr to another brand of codec? The charts below will help. If you have experience with codecs not listed, or need further information on compatibility, please contact Telos. 


Chart of Zephyr-Compatible Codecs:


(Scroll down for application notes)



General Notes:

  • YES=Compatible. Zephyr Layer II operation requires Layer III+II firmware and hardware.

  • No=Mode supported by other codec is not compatible with Zephyr.

  • N/S=Not supported by other codec.

  • Zephyr firmware version 2.50 and later supports ISO/MPEG Layer II at 48kHz sample rate. Firmware version 2.69 and later also supports ISO/MPEG Layer II Mono at 24kHz.

  • Zephyr supports "CCS CDQ protocol compatible" channel splitting for ISO/MPEG Layer II stereo and mono 128 modes.

  • Zephyr models 9200, 9201 or 9202 required for stereo and mono-128 modes.

  • Zephyr G.722 uses statistical recovery sync. G.722 sample rate is fixed at 16kHz regardless of menu setting.


CCS Notes:

  • CDQ 1000: Switch off H.221 (DIP switch 7 , on back, in down position; to "AUTO" mode) on CDQ to transmit from CDQ to Zephyr. Terminal adaptor must have "BONDING" turned off and be set to 64/56Kbps. 24kHz requires MPEG compatibility.

  • CDQ 2000: Switch to "Decoder independent from encoder" (Decoder DIP switch #6 in up position; "INDEPENDENT"). Terminal adaptor must have "BONDING" turned off and be set to 64/56Kbps.

  • CDQPrima: Must be set to front panel option "DECODER/GENERAL/INDEP=YES" OR Serial port command "DIN YES". To transmit G.722, sample rate must be set to 16kHz. Primas with serial numbers beginning with "2" have Layer III. Zephyr firmware version 2.69 and later may be required to communicate in certain Layer III modes or dropouts may occur.


Comrex Notes:

  • DX200: must have ERROR PROTECTION set to "ON" and IMUX set to "TELOS/CCS" or "CCS". Terminal adaptor must have "BONDING" turned off and be set to 64/56Kbps.

  • Nexus: must have "H.221" off.


Dialog4 Notes:

  • Zephyr can transmit to DIALOG4 in the modes indicated. For DIALOG4 to Zephyr compatibility, Zephyr firmware version 2.69 or later must be used, and compatibility mode set correctly. MUSICTAXI must have "Configuration/ISDN accept mode" set to "ALL" AND "Configuration/ISDN mode" set to "RI," "DNRI" or "DNR" depending on firmware version.


Nagra Note:

  • Nagra "SYNC" mode must be set to "SRT".


RE Note:

  • Modes which require greater than 64kbps will not work. Zephyr can receive Layer II JStereo, Stereo and Dual from RE when transmitted at 64kbps (single B channel).

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