Chapter 8 Network Address Translation (NAT)
Use this screen to enable or disable the SIP (VoIP) ALG in the
Figure 87 NAT > ALG
Each field is described in the following table.
Table 55 NAT > ALG
LABEL | DESCRIPTION |
Active SIP ALG | Select this check box to allow SIP sessions to pass through the P- |
| |
| the sending of voice signals over Internet Protocol. |
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Apply | Click Apply to save your customized settings. |
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8.7 Technical Reference
The following section contains additional technical information about the P-
Port Forwarding: Services and Port Numbers
The most often used port numbers are shown in the following table. Please refer to RFC 1700 for further information about port numbers. Please also refer to the Supporting CD for more examples and details on port forwarding and NAT.
Table 56 Services and Port Numbers
SERVICES | PORT NUMBER |
ECHO | 7 |
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FTP (File Transfer Protocol) | 21 |
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SMTP (Simple Mail Transfer Protocol) | 25 |
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DNS (Domain Name System) | 53 |
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Finger | 79 |
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HTTP (Hyper Text Transfer protocol or WWW, Web) | 80 |
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POP3 (Post Office Protocol) | 110 |
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NNTP (Network News Transport Protocol) | 119 |
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SNMP (Simple Network Management Protocol) | 161 |
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| 193 |
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