363-206-295
Technical Specifications
10-22 Issue 1 December 1997
SONET Overhead Bytes 10
The only use of SONET overhead bytes for proprietary signaling is the K2 byte for synchronization
messaging. See Section 6, "System Planning and Engineering," of 363-206-200
DDM-2000 OC-3
and OC-12 Multiplexers Applications, Planning, and Ordering Guide,
for more information on
synchronization messaging.
Performance 10
Wander/Jitter 10
■ For SONET optical interfaces, the maximum time interval error (MTIE) does not exceed 60
nanoseconds phase variation when timed with a wander-free reference.
■ Jitter transfer, tolerance, and generation requirements are met as specified in TR-253 and
TR-499.
■ The SONET interface meets the T1.101 OC-N output short term stability mask.
Signal Performance 10
■ For systems interfacing at the DS3 rate, the number of errored seconds, during a 2-hour,
one-way loopback test, is less than 72.
■ The BER is less than 10
-9
for DS3 rates. Burst error seconds are excluded.
■ The frequency of burst errored seconds, other than those caused by protection switching
induced by hard equipment failures, average less than four per day.
Synchronization 10
Synchronous Timing Generator (BBF2/BBF2B) 10
The TGS circuit pack meets the specifications of GR-253-CORE, SONET Transport Systems
Generic Criteria. The TGS circuit pack supports three timing modes:
■ External timing (phase-locked mode): Locked to external Stratum 3
(±4.6 ppm) or better DS1 reference.
■ Line-timing: Locked to recovered clock from an OC-N signal.
■ Free-running: Timing derived from high-stability temperature-compensated voltage-
controlled crystal oscillator (TCVCXO) with a long-term accuracy of ±15 ppm (−40°C to
+75°C).
Holdover mode is entered on failure of external timing or line-timing reference, providing a
temperature stability of ±8.8 ppm (−40°C to +75°C). 24-hour holdover stability will be better than
±4.6 ppm.
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