Telos Zephyr Xstream - Manual (Page 143)

USER’S MANUAL
Section 6: AUDIO CODING REFERENCE 131
also useful for network operations centers, or other busy facilities, where
the equipment must be stretched as far as possible.
Connectivity
The Xstream's MPEG bit streams follow standard ISO format, and may be used to communicate
with any codec that supports this standard. In modes that require two ISDN channels, the
channel‐splitting (IMUX) method becomes an issue.
Layer 2 is widely supported by many manufacturers. The Zephyr Xstream supports the CDQ
splitting scheme, so it may be used to communicate with the codecs from a variety of vendors
that support this mode.
In Layer‐3 Zephyr set the standard. Other codecs that support Layer‐3 use the FhG/Telos
protocol developed for Zephyr classic (Buchta splitting).
Telos has long been a proponent of international standards for codec interoperability. The
specifications of our IMUX system, developed for AAC and AAC‐LD, is available without royalty,
and is published on our web site for reference by other manufacturers.
The Xstream’s G.722 mode offers connectivity with almost all codecs that use this coding
method, and which do not use the rare H.221 framing scheme. We support the more common
"SRT" (Statistical Recovery Timing) method.
Ancillary data transmission is not standardized and is therefore not available between codecs
made by different manufacturers.