routing
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... client is responsible for loop detection.
The rest of the resolution of the routing is done as described above.
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There are a number of countries (and other numbering environments) in
which there are multiple providers of call routing and number/name-
translation services. In these areas, any system that permits users,
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... services. In these areas, any system that permits users,
or putative agents for users, to change routing or supplier
information may provide incentives for changes that are actually
unauthorized (and, in some cases, for denial of legitimate change
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... ITU-T SG2, Working Party 1/2
(Numbering, Routing, Global Mobility and Service Definition), the
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