ZyXEL Router Prestige 334 User Manual

Prestige 334 User’s Guide
Appendix B PPPoE332
Appendix B
PPPoE
PPPoE in Action
An ADSL modem bridges a PPP session over Ethernet (PPP over Ethernet, RFC 2516) from 
your computer to an ATM PVC (Permanent Virtual Circuit) which connects to a DSL Access 
Concentrator where the PPP session terminates (see the next figure).  One PVC can support 
any number of PPP sessions from your LAN. PPPoE provides access control and billing 
functionality in a manner similar to dial-up services using PPP.
Benefits of...

Prestige 334 User’s Guide
333Appendix B PPPoE
Figure 183   Single-Computer per Router Hardware Configuration
How PPPoE Works
The PPPoE driver makes the Ethernet appear as a serial link to the computer and the computer 
runs PPP over it, while the modem bridges the Ethernet frames to the Access Concentrator 
(AC).  Between the AC and an ISP, the AC is acting as a L2TP (Layer 2 Tunneling Protocol) 
LAC (L2TP Access Concentrator) and tunnels the PPP frames to the ISP.  The L2TP tunnel is 
capable of...

Prestige 334 User’s Guide
Appendix C PPTP334
Appendix C
PPTP
What is PPTP?
PPTP (Point-to-Point Tunneling Protocol) is a Microsoft proprietary protocol (RFC 2637 for 
PPTP is informational only) to tunnel PPP frames. 
How can we transport PPP frames from a computer to a broadband 
modem over Ethernet?
A solution is to build PPTP into the ANT (ADSL Network Termination) where PPTP is used 
only over the short haul between the computer and the modem over Ethernet. For the rest of 
the connection, the PPP...

Prestige 334 User’s Guide
335Appendix C PPTP
PPTP Protocol Overview
PPTP is very similar to L2TP, since L2TP is based on both PPTP and L2F (Cisco’s Layer 2 
Forwarding). Conceptually, there are three parties in PPTP, namely the PNS (PPTP Network 
Server), the PAC (PPTP Access Concentrator) and the PPTP user. The PNS is the box that 
hosts both the PPP and the PPTP stacks and forms one end of the PPTP tunnel. The PAC is the 
box that dials/answers the phone calls and relays the PPP frames to the PNS. The...

Prestige 334 User’s Guide
Appendix C PPTP336
Figure 187   Example Message Exchange between Computer and an ANT
PPP Data Connection
The PPP frames are tunneled between the PNS and PAC over GRE (General Routing 
Encapsulation, RFC 1701, 1702). The individual calls within a tunnel are distinguished using 
the Call ID field in the GRE header.  

Prestige 334 User’s Guide
337Appendix C PPTP 

Prestige 334 User’s Guide
Appendix D NetBIOS Filter Commands 338
Appendix D
NetBIOS Filter Commands
The following describes the NetBIOS packet filter commands.
Introduction
NetBIOS (Network Basic Input/Output System) are TCP or UDP broadcast packets that 
enable a computer to connect to and communicate with a LAN. 
For some dial-up services such as PPPoE or PPTP, NetBIOS packets cause unwanted calls.
You can configure NetBIOS filters to do the following :
• Allow or disallow the sending of NetBIOS...

Prestige 334 User’s Guide
339 Appendix D NetBIOS Filter Commands
The filter types and their default settings are as follows.
NetBIOS Filter Configuration
Syntax:sys filter netbios config  
where
Table 113   NetBIOS Filter Default Settings
NAMEDESCRIPTIONEXAMPLE
Between LAN 
and WANThis field displays whether NetBIOS packets are blocked or forwarded 
between the LAN and the WAN.Block
IPSec 
PacketsThis field displays whether NetBIOS packets sent through a VPN 
connection are blocked or forwarded. Forward...

Prestige 334 User’s Guide
Appendix E Log Descriptions340
Appendix E
Log Descriptions
Configure centralized logs using the embedded web configurator; see online help for details. 
This appendix provides descriptions of example log messages.
 
Table 114   System Error logs
LOG MESSAGEDESCRIPTION
%s exceeds the max. number 
of session per host!This attempt to create a NAT session exceeds the maximum 
number of NAT session table entries allowed to be created per 
host.
Table 115   System Maintenance Logs
LOG...

Prestige 334 User’s Guide
341Appendix E Log Descriptions
Table 116   UPnP Logs
LOG MESSAGEDESCRIPTION
UPnP pass through FirewallUPnP packets can pass through the firewall.
Table 117   ICMP Type and Code Explanations
TYPECODEDESCRIPTION
0Echo Reply
0Echo reply message
3Destination Unreachable
0Net unreachable
1Host unreachable
2Protocol unreachable
3Port unreachable
4A packet that needed fragmentation was dropped because it was set to Dont 
Fragment (DF)
5Source route failed
4Source Quench
0A gateway may...