Technical Reference - ZyXEL Communications P870HNU-51B User Manual

Chapter 8 Network Address Translation (NAT)
Use this screen to enable or disable the SIP (VoIP) ALG in the Device. To access this screen, click
NAT > ALG.
Figure 59 NAT > ALG
Each field is described in the following table.
Table 47 NAT > ALG
LABEL
Enable SIP ALG
Apply

8.6 Technical Reference

The following section contains additional technical information about the Device features described
in this chapter.
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 48 Services and Port Numbers
SERVICES
ECHO
FTP (File Transfer Protocol)
SMTP (Simple Mail Transfer Protocol)
DNS (Domain Name System)
Finger
HTTP (Hyper Text Transfer protocol or WWW, Web)
POP3 (Post Office Protocol)
NNTP (Network News Transport Protocol)
SNMP (Simple Network Management Protocol)
SNMP trap
PPTP (Point-to-Point Tunneling Protocol)
156
DESCRIPTION
Select this check box to allow SIP sessions to pass through the Device. SIP is a
signaling protocol used in VoIP (Voice over IP), the sending of voice signals over
Internet Protocol.
Click Apply to save your customized settings.
PORT NUMBER
7
21
25
53
79
80
110
119
161
162
1723
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