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Chapter 1 Introducing Linksys IP Phones
Technology Background
•Using Linksys IP Phones with a Firewall or Router, page
•Using Linksys IP Phones with a Firewall or Router, page
Session Initiation Protocol
Linksys 900 Series IP phones are implemented using open standards, such as Session Initiation Protocol (SIP), allowing interoperation with all ITSPs supporting SIP. Figure
Figure 1-2 SIP Requests and Responses
SIP UA
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SIP Proxy
RTP
SIP Proxy
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SIP Proxy
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SIP UA
In a SIP VoIP network, when the SIP proxy receives a request from a UAS for a connection and it does not know the location of the UAC, it forwards the message to another SIP proxy in the network. Once the UAC is located and the response is routed back to the UAS, a direct
Using Linksys IP Phones with a Firewall or Router
When using a Linksys IP phone behind a firewall or router, make sure that the following ports are not blocked:
•SIP
•RTP
If security is not a concern in your environment, you can consider disabling SPI, if this function exists on your firewall.
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| Linksys IP Phone Administrator Guide |
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| Firmware Version 5.1 |
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