put) and clock (input) interfaces Annex A, "Wander reference models and wander budgets" Although G.824 is more than 20 years old, a correction was published in 2015. To read the com- plete recommendation, you will need both documents, which are accessible at the following link. Because this recommendation applies to circuits based on the 1544-kbps system, it interests only those using North American-type circuits, which includes the United States, Canada, and Japan. Link to recommendation: https://handle.itu.int/11.1002/1000/12560 G.825: The Control of Jitter and Wander Within Digital Networks Which Are Based on the Synchronous Digital Hierarchy (SDH) ITU-T G.825 covers the network limits for jitter and wander for traffic and synchronization net- works based on the SDH hierarchy. The architectural aspects of the SDH networks are defined in G.803 with optical, electrical, and other information across numerous other recommendations. From the scope of the recommendation: The scope of this ITU-T Recommendation is to define the parameters and the relevant val- ues that are able to control satisfactorily the amount of jitter and wander present at the SDH network-network interfaces (NNI). As seen previously, jitter and wander requirements for PDH and synchronization networks based on the first-level bit rate of 2048 kbps are specified in G.823. Networks based on the first-level bit rate of 1544 kbps are covered in G.824. This recommendation includes the following main topics and appendixes: Network limits for synchronous transport module (STM-N) interfaces (output jitter, output wander) Jitter and wander tolerance of STM-N input interfaces Jitter and wander generation and transfer Appendix I, "Relationship between network interface jitter requirements and input jitter tolerance" Appendix II, "Measurement methodology for output wander of synchronous interfaces" G.825 is also more than 20 years old, but an erratum was published in 2001, and an amendment was published in 2008. The amendment added information on STM-256 (40