ITU-T - International Telecommunication Union/ITU Telcommunication Sector
适用范围
The scope of this ITU-T Recommendation is to define the parameters and the relevant values that are able to control satisfactorily the amount of jitter and wander present at the SDH network-network interfaces (NNI). SDH network interfaces@ to which this ITU-T Recommendation is applicable@ are defined in terms of bit rates and frame structures in ITU-T Recommendation G.707; their electrical characteristics are described in ITU-T Recommendation G.703 and the optical characteristics in ITU-T Recommendations G.957 and G.691. Additional information regarding the architecture of SDH networks is found in ITU-T Recommendation G.803. Jitter and wander requirements for PDH and synchronization networks are specified in ITU-T Recommendation G.823@ for networks based on the first level bit rate of 2048 kbit/s@ and in ITU-T Recommendation G.824 for networks based on the first-level bit rate of 1544 kbit/s. The jitter and wander control philosophy is based on the need: ?C to recommend a maximum network limit that should not be exceeded at any relevant interface; ?C to recommend a consistent framework for the specification of individual digital equipment (i.e. jitter and wander transfer@ tolerance and generation requirements); ?C to provide sufficient information and guidelines for organizations to measure and study jitter and wander accumulation in any network configuration.