On Networks N150RM User Manual - Manual (Page 31)

Modem Router Setup
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N150 Wireless ADSL2+ Modem Router N150RM
• You have problems connecting to your ISP or other Internet service, and the technical
support of either the ISP or On Networks recommends changing the MTU setting. These
web-based applications might require an MTU change:
- A secure website that does not open, or displays only part of a web page
- Yahoo email
- MSN portal
- America Online’s DSL service
• You use VPN and have severe performance problems.
• You used a program to optimize MTU for performance reasons, and now you have
connectivity or performance problems.
Note:
An incorrect MTU setting can cause Internet communication
problems. For example, you might not be able to access certain
websites, frames within websites, secure login pages, or FTP or
POP servers.
If you suspect an MTU problem, a common solution is to change the MTU to 1400. If you are
willing to experiment, you can gradually reduce the MTU from the maximum value of 1500
until the problem goes away. The following table describes common MTU sizes and
applications.
Table 2. Common MTU sizes
MTU Application
1500 The largest Ethernet packet size and the default value. This setting is typical for
connections that do not use PPPoE or VPN, and is the default value for On Networks
modem routers, adapters, and switches.
1492 Used in PPPoE environments.
1472 Maximum size to use for pinging. (Larger packets are fragmented.)
1468 Used in some DHCP environments.
1460 Usable by AOL if you do not have large email attachments, for example.
1458 Used in PPPoA environments.
1436 Used in PPTP environments or with VPN.
1400 Maximum size for AOL DSL.
576 Typical value to connect to dial up ISPs.
 To change the MTU size:
1. Select Setup > WAN Setup.
2. In the MTU Size field, enter a value from 64 to 1500.