VG3300 series user guide
11.3. Inbound AuthenticationYou need to configure inbound authentication if you request authentication for other SIP phone to call you.
Configuration
WEB Page: ADVANCED \ SIP INBOUND AUTHENTICATION
11.4. FAXFor VG3300 software version 1.05 or above, SIP-based T.38 Fax protocol is applied. Any brand SIP gateway with SIP-based T.38 Fax protocol can transmit FAX with each other. T.38 is FAX protocol and it has better performance and better successful transmission rate. However, SIP device that does not support SIP-based T.38 still can transmit and receive FAX with VG3300 by G.711 codec. G.711 codec uses more bandwidth, so it may not as good as SIP-based T.38 protocol if bandwidth control is the key factor of the network.
Setup method is listed below:
1.Web folder: “Channel”
Enable T.38 Fax Relay support. Configure it to Yes
2. Warm-Restart the system
Note: For FAX transmission, two gateways will change to SIP-Based T.38 Protocol automatically if