Specifications

General Information Guide
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R2
The 3300 R2 NSU provides access to the R2 National Public Switched Telephone Network (PSTN)
with MF-R2 digital trunk signaling. The 3300 R2 NSU supports the CCITT Blue Book, Volume VI,
Fascicle VI.4, Specifications of Signaling System R2, Recommendations Q.44o to Q.490 (with the
exception of Q.479 Echo Suppression, Q.490 Test Calls and international signals).
Many countries use R2 signaling but do not adhere to the CCITT recommendations in their entirety.
The 3300 ICP is completely flexible and supports regional variations of the R2 protocol. Line
signaling, tone interpretation, and timing parameters for the converter can be adapted to suit any
national or regional requirement. For example
• Line signaling features allow you to program up to four bits to define the incoming and
outgoing patterns for line signals such as Idle and Answer
• Register signaling features allow you to program the type of address signaling termination
(signaled or timed) and whether signaling should be fully-compelled or semi-compelled.
These features allow the individual definition of each register signaling tone.