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Bandwidth limitations in bridged mode

New Poster

Bandwidth limitations in bridged mode

I have 1g service and a technicolor xb6 modem.  When the modem is in router mode, i can get ~930mbps (xfinity speed test) from a wired connection.  When i switch over to bridged mode and add my own router (asus ac86u or netgear x10) i only get ~600mbps.  I had disabled qos, firewall and monitoring services on both routers when comparing the performance.  Now here’s the part that’s really confusing.  If i leave the router connected and disable bridged mode, meaning there are two routers between the coax and the computer (the cable modem and the netgear), i get 930mbps again.  So this isnt a connection, cable, router or link problem.  It appears that the router in bridged mode can/will not allow full speed.   Speed testing at various sites has given a wide distribution if results.  For example, xfinity speed test gives different values depending on if you use ip6 or ip4.  In router mode the result is 930 and 600 respectively.  In bridged mode its 400 and 600.  Very strange results that i was hoping would explain the difference but it definitely doesnt when ip6 vs ip6 is over 500 

mbit difference.  For other speed tests that dont have the ip options bridged mode is 300 mbit while non bridged is 400.  So it seems there is a 25-30% drop in performance when bridged is selected.  Can anyone explain this?

Expert

Re: Bandwidth limitations in bridged mode

Can't explain it and have seen it many times here before. All I know is that fact would be more than enough for me to stop renting their device and save the rental fee, buy my own straight DOCSIS 3.1 capable straight modem and use my capable router instead !! 



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New Poster

Re: Bandwidth limitations in bridged mode

I almost bought one today, however, ive already spent 400 on the router which it turns out i didnt need.  So i am holding off until i know for sure thats the route to go.  Plus i have the tripple play, so from what i can tell is that i must have a 3.1 with phone (even though in the last 5 years ive never even plugged a phone in.  I briefly looked at the netgear one but quite a few reviews said it fails after two months.

Expert

Re: Bandwidth limitations in bridged mode

O/k well good luck with this !! Smiley Happy



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New Poster

Re: Bandwidth limitations in bridged mode

So even more weirdness ensued.  If i connected my macbook directly to the modem while it was in bridged mode it would run 930 mbits.  I showed all this behavior to an xfinity service person today and neither of us could explain why this was happening.  So i am going to just be happy with what ive got and return the new router i bought as it doesnt really help.  Maybe one day ill figure it out.  What i did learn though is ip4 vs ip6 speed tests result in different speeds and If the external router isnt set to work with ip6 then the speed is affected negatively.  

Official Employee

Re: Bandwidth limitations in bridged mode

@Bbeal

 

Thank you for posting to the Xfinity Forum. Please let us know if there is more we can assist you with in the future. 


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