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Simultaneous support single exchange and double exchange in M3UA

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Can one implementation support single exchange and double exchange models of IPSP at the same time ? Or does it have to be configured and only one of the models can be active at a time ? Is there any M3UA procedure which can help in dynamic negotiation of SE/DE models.

posted Aug 2, 2013 by Sanketi Garg

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1 Answer

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Best answer

SE support is mandatory. DE support is optional. Therefore, when an implementation supports DE it must also support SE.

Some implementations might only support one model at a time for a given AS/ASP, but that is a (minor) limitation of that implementation.

There is no need for negotiation: all implementations supporting IPSP MUST support SE: so just use that.

Nevertheless, when an IPSP sends an ASP-UP message and receives an ASP-UP message in response, or sends an ASP-ACTIVE message and receives an ASP-ACTIVE message in response, it can determine that the peer is using DE mode and proceed accordingly.

It can also determine DE mode from REGREQ messages in a similar manner when registration is used.

answer Aug 18, 2013 by anonymous
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