Nexland why 1472 answer

Bob Carrick · Post by **Bob Carrick** » Thu Feb 21, 2002 10:20 am

"The RFC states that the MTU for PPPoE is 1492, however when using routers, some web sites may not be visible at this setting. If we follow the RFC, we will see some problems. It is not that we will not follow the RFC, it is a matter of customer satisfaction to keep the MTU lower, and not risking unviewable sites."

This was my response "Can it not be set to 1472 by default but still give "Power Users" the option to set to 1492, that is what we want. EnterNet is no different, default is 1454, but Power users can up it to 1492."

rmrucker · Post by **rmrucker** » Thu Feb 21, 2002 10:29 am

Sorry to say this, but that sounds like BS to me. Gee, Nexland certainly is NOT the market leader in routers. If every other router can use PPPoE with an MTU of 1492, then so should theirs. If you look at all the people that use PPPoE via software (WinPoEt, EnterNet, RASPPPoE, etc.) and all the people that use other routers (Linksys, D-Link, etc.) -- you would hardly even notice the Nexland users. But surprisingly, they need a lower MTU to view some sites. BS.

Bob Carrick · Post by **Bob Carrick** » Thu Feb 21, 2002 10:30 am

Actually it is a very truthful answer. There are many cases where customers need a lower MTU then 1492, that is why EnterNet install at 1454, Windows XP installs at 1480, WinPoet at sometimes as low as 1372. Many Sympatico customers need 1454 to get all sites to work.

rmrucker · Post by **rmrucker** » Thu Feb 21, 2002 10:43 am

In *almost* all cases we have been able to defeat the MTU limitations set by these programs and routers. And it each case (except for the WinPoET Tunnel and Sympatico) the connections were as good or better.

Certianly, other routers do NOT need this limitation -- Linksys corrected their limitation about one year ago *without an ill effect*. Also, in every case I have seen we have increased EnterNet to 1492 with no problems. I have a hard time swallowing their explanations.

EnterNet adamantly states that 1454 is the best for PPPoE. Yet MS uses 1480, Nexland uses 1472, etc. There is NO consistency in any of this. If there was truly a best MTU for PPPoE, then EVERYONE would use it.

Just my opinion.

Bob Carrick · Post by **Bob Carrick** » Thu Feb 21, 2002 10:47 am

1492 is the PPPoE RFC, but some ISPs don't follow this, resellers of other Telco's PPPoE may have additional header depending on how traffic is passed from the telco to the ISP, we have a case of that right here in Ottawa, where the MTU needs to be 1472. I've seen many cases where 1492 will not work. And no not just Sympatico, though it is the dominent ISP.

I agree with 1472, but I do not agree with us not having the choice to up it to 1492 for the 90% of cases where 1492 will work perfectly.

Lobo · Post by **Lobo** » Thu Feb 21, 2002 10:51 am

The bottom line, please, what should it be set to

Bob Carrick · Post by **Bob Carrick** » Thu Feb 21, 2002 10:52 am

Well at this moment in time we have no choice in Nexland routers, 1472 is the maximum. I'm doing what I can to get the next firmware to give us the option.

Lobo · Post by **Lobo** » Thu Feb 21, 2002 10:55 am

This is very confusing, so I will call on you Bob if that is cool

rmrucker · Post by **rmrucker** » Thu Feb 21, 2002 12:48 pm

I think their might be pockets where the ISP is forcing a limited MTU (e.g., Ottawa is the best example anyone has ever come up with). But for most of the US, this type of limitation just does not exist.

The major exception I can find here is where the ISP is forcing the use of WinPoET with TunnelMode. Every other PPPoE Client and router can use 1492.

I think if even 5-10% of users could not use and MTU or 1492, this would amount to thousands of people and a Customer Service nightmare. Where is this nightmare?

Bob Carrick · Post by **Bob Carrick** » Thu Feb 21, 2002 1:52 pm

I answer the question to at least 1 person every day ot couple of days where they need to lower the MTU, a lot of people think it's something wrong with the internet and leave it at that. Remember most people don't know as much as we do. Also 90% of people stick with what they are given hence would never see the problem. 10% of tweak or switch software or use a router, so 5 - 10% of that is a very low number.

Kirby Smith · Post by **Kirby Smith** » Sat Feb 23, 2002 10:25 am

Thanks for the update Bob. I still plan to eventually experiment with Verizon to check its WinPoet limitations, and possibly thereby infer its PPPoE max MTU limitations. Unless someone here already knows that Verizon DSL will work with PPPoE at 1492 and save me a bunch of configuation and experiment time. In the latter case, it just remains for Nexland to make 1492 optional with 1472 the default. After all, those who find it won't work can change it back. Nonetheless, I realize that the speed improvement is slight, and that the effort Nexland would have to make to add and test the new software might well outweigh the download time savings by whatever fraction of their customers actually change the MTU.

kirby at 1472 PPPoE w/Nexland ISB SOHO