ISDN access line data link layer and network layer maintenance

The authors discuss surveillance-based maintenance support for the ISDN (integrated services digital network) data link and network layers. The need for each layer to be monitored separately and the tools that can be used to maintain these layers (including testing tools) are identified. These tools are being considered within the T1M1.2 ISDN maintenance operations sub-working group and will complement the layer 1 maintenance tools (e.g. cyclic-redundancy-check-based performance monitoring) planned by T1M1.2.<
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