ZyXEL Communications Prestige 642R Series - Manual (Page 63)

Prestige 642R Series ADSL Router
4-2 Remote Node Configuration
4.1.2 Encapsulation and Multiplexing Scenarios
For Internet access you should use the encapsulation and multiplexing methods used by your ISP. For
LAN-to-LAN applications, e.g., branch office and corporate headquarters, prior mutual agreement on
methods used is necessary because there is no mechanism to automatically determine encapsulation or
multiplexing. Selection of which encapsulation and multiplexing methods to use depends on how many
VCs you have and how many different network protocols you need. The extra overhead that PPP over
Ethernet (PPPoE) and ENET ENCAP encapsulation entail makes them a poor choice in a LAN-to-LAN
application. Here are some examples of more suitable combinations in such an application.
Scenario 1. One VC, Multiple Protocols
PPP (RFC-2364) encapsulation with VC-based multiplexing is the best combination because the extra
protocol identifying headers that LLC-based multiplexing uses is not needed. The PPP protocol already
contains this information.
Scenario 2. One VC, One Protocol (IP)
Select RFC-1483 encapsulation with VC-based multiplexing requires the least amount of overhead (0
octets). However, if there is a potential need for multiple protocol support in the future, it may be safer to
select PPP encapsulation instead of RFC-1483, so you do not need to reconfigure either machine when the
time comes.
Scenario 3. Multiple VCs
If you have an equal number (or more) of VCs than the number of protocols, then select RFC-1483
encapsulation and VC-based multiplexing.
When Menu 11.1 – Remote Node Profile appears fill in the fields as described in the following table to
define this remote profile. The Remote Node Profile Menu Fields table shows you how to configure the
Remote Node Menu.