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In the infrastructure example above, L2 would be listed as AAA server for L2-IDP and L3-IDP on L1, while L2A would be listed as AAA server for L2A-IDP. On L2, L3 would be listed as the AAA server for L3-IDP.
The timings improve when the top-level trust router has a fairly liberal key expiry policy and subsequent requests do not need to request TID keys for the APC itself.
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