Snom 4S manual Overview

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[ S N O M 4 S N A T F I L T E R ]

The first exception is a REGISTER request. When a user agent tries to register and needs the support of the filter, the filter will set up a local data structure representing the user agents. It will make sure that the connection to the user agents stays alive. It will also make sure that requests destined to the user agents will be forwarded properly.

The second exception is an SDP attachment. The filter checks if the user agent needs support (or must be recorded) and will in that case add a local contact to the SDP that can be used for media relay.

The third exception occurs when the filter queries a web server for routing information. In this case, it will send a provisional response to stop the UAC from repeating messages.

These three exceptions make sure that all user agents will work behind NAT, no matter what NAT-type or how many NAT-levels are being used. If user agents support ICE, they will automatically find the shortest media path to the other party (peer-to-peer).

8 • Overview

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Contents Snom 4S NAT Filter Admin Manual Snom 4S NAT Filter Version Table of Contents Snmp Overview Features ApplicationsSnom technology AG Overview Architecture NAT Filter and SIPNAT Symmetrical RTP Signalling SIPHow does NAT work? Media RTP Classification of User AgentsProbing Media Paths Role of the NAT FilterOptimizing the Media Path for Symmetrical NATSBC Behaviour RegisteringRTP Relay Snom technology AG Scaling and Redundancy NATDetecting the right NAT Filter STUN/ICE-Aware User Agents Requirements on User AgentsNon NAT-Aware User Agents Defining the Maximum Session Time Architecture Installation WindowsInstallation Snom technology AG Installation Snom technology AG Linux Rpm -ihv snomnatf-2.10.*.rpm Installation Logging Port BindingStandard Port Random Port System Settings LoggingPreparing Recovery General Outound ProxyMedia Ports Port BudgetsMedia Relay Controlling RoutingMultiple 2xx Handling Maximum Packet Size ChallengingTrusted Addresses Removing Headers Silence SuppressionConnection Oriented Media Clir Addresses Codec ControlWeb Server Integration Timeout Settings Register TimeoutsCall Timeouts Security Settings Snom technology AG Outbound Proxy List System Information Server LogTrace Call History Current Ports Currently Handled UA Memory StatisticsConfiguration Web Server Integration Authentication Interface to the Web ServerSnom technology AG Web Server Integration Registration Call Initiation Snom technology AG Call Termination Snom technology AG Web Server Integration Setup of the SBC Setup of the ToolsAvailable OID OIDSnom technology AG Snmp Checklist for Installation Checklist for Installation Reader‘s Feedback Snom technology AG All rights reserved