Use SIP Message Manipulation for Topology Hiding

The device intrinsically employs topology hiding, limiting the amount of topology information displayed to external parties (i.e., un-trusted networks). This anonymous information minimizes the chances of directed attacks on your network.

The device employs topology hiding by implementing back-to-back user agent (B2BUA) leg routing:

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Strips all incoming SIP Via header fields and creates a new Via value for the outgoing message

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Each leg has its own Route/Record Route set

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Generates a new SIP Call-ID header value (different between legs)

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Changes the SIP Contact header to the device's address

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Performs Layer-3 topology hiding by modifying the source IP address in the SIP IP header (for example, IP addresses of ITSPs equipment such as proxies, gateways, and application servers can be hidden from outside parties)

In addition, to enhance topology hiding, you can modify the SIP To header, From header, and/or Request-URI host name. This can be done using the Message Manipulation table or the IP Group (for SIP URI host part manipulations). The Message Manipulation table also supports Regular Expressions (Regex).