Router blocking MTU?

[Xorgroth]

I have a Zoom X5 5654 DSL gateway, currently on the TCP analyzer it says my MTU could be higher but looks like a router is blocking me. Supposed to be a 7mb connection and don't use PPPoE. Though do use PPPoA and the specific message is "MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput. If you are using a router, it could be limiting your MTU regardless of Registry settings."

Thanks,
Xorg

Code: Select all

« SpeedGuide.net TCP Analyzer Results » 
Tested on: 10.21.2008 19:29 
IP address: 75.174.xx.xxx 
 
TCP options string: 0204058c0103030201010402 
MSS: 1420
MTU: 1460 
TCP Window: 261280 (multiple of MSS) 
RWIN Scaling: 2 bits (2^2=4) 
Unscaled RWIN : 65320 
Recommended RWINs: 65320, 130640, 261280, 522560, 1045120 
BDP limit (200ms): 10451kbps (1306KBytes/s)
BDP limit (500ms): 4180kbps (523KBytes/s) 
MTU Discovery: ON 
TTL: 42 
Timestamps: OFF 
SACKs: ON 
IP ToS: 01010000 (80) 
    Precedence: 010 (immediate)
    Delay: 1 (low delay)
    Throughput: 0 (normal throughput)
    Reliability: 0 (normal reliability)
    Cost: 0 (normal cost)
    Check bit: 0 (correct)
DiffServ: AF22 010100 (20) - Assured Forwarding class 2, medium drop precedence (RFC 2597).

[mccoffee]

If i could find a manual for that router i can give you better instruction hwoever though from reading information from another forum if you login to the router the mtu is two places lan ,and wan.
In ther roughters configuration page it should be a 192.168.x.x adrees
If you ISP IS pppo3 set the wan tof 1492 pppoa 1500
In the lan mtu set it to 1500

[dlsayremn]

mccoffee try here for users manual

http://www.zoom.com/documentation/adsl/ ... de_Eng.pdf

[Xorgroth]

Hmm, router is set for 1500..should plugin to it directly, might be the switch I'm using.

EDIT: Nope, same thing oddly...

[mccoffee]

Thanks for that link in the manual the only thing i noticed that can be throwing the mtu is off is the ecapsulation type try calling the ISP ,and make sure the ecaplusation is set correctly on the zoom

if you do change the encplasulation the mtu should change automaticlly.
from what i'm reading here