How can I obtain highest compatibility between my Snom phone and any RFC compliant SIP registrar

In case of registration problems with unknown RFC 3261 compliant SIP registrars the following options may be configured via the phone´s web interface:

Identity page -> SIP tab:

• Long SIP-Contact (RFC3840) -> "off"

• Support broken Registrar -> "on"

Advanced -> QoS/Security:

• Filter Packets from Registrar -> "off"

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