Justin Lee
asked on
Ciena 3930 (Fiber modem) --> any router slows down bandwidth by 80%
This is our current small office's setup:
Ciena 3930 fiber modem (provided by at&t)
ethernet cable connected to modem (port #2)
cable drop through ceiling --> office IT room
1 port switch converting cable into RJ45 IN
Connecting my laptop directly with an ethernet cable into this port, using the static IP provided by my ISP, I get my full bandwidth during speed tests (100mbps down/up)
Connect a router into the port (Apple Airport Extreme) --> connect via wifi to router
speed test shows ~15mbps down/ ~50mbps up
Connect via ethernet cable into router
speed test shows ~15mbps down / ~50mbps up
Thinking the router was having issues, I brought my Asus AC1900 from home, factory reset it, and set it up with the static IP, etc. and am getting the same results as from the Apple router.
As soon as the router is removed, I can get a full 100/100 connection directly to my laptop
Are there any compatibility issues with "enterprise grade" fiber modems and "consumer grade" routers that could be causing this?
If you would like any other information that might help, please let me know and I will update ASAP.
Thank you
Ciena 3930 fiber modem (provided by at&t)
ethernet cable connected to modem (port #2)
cable drop through ceiling --> office IT room
1 port switch converting cable into RJ45 IN
Connecting my laptop directly with an ethernet cable into this port, using the static IP provided by my ISP, I get my full bandwidth during speed tests (100mbps down/up)
Connect a router into the port (Apple Airport Extreme) --> connect via wifi to router
speed test shows ~15mbps down/ ~50mbps up
Connect via ethernet cable into router
speed test shows ~15mbps down / ~50mbps up
Thinking the router was having issues, I brought my Asus AC1900 from home, factory reset it, and set it up with the static IP, etc. and am getting the same results as from the Apple router.
As soon as the router is removed, I can get a full 100/100 connection directly to my laptop
Are there any compatibility issues with "enterprise grade" fiber modems and "consumer grade" routers that could be causing this?
If you would like any other information that might help, please let me know and I will update ASAP.
Thank you
The Ciena 3930 is a switch, not a modem or router.
Your MTU should be set at 1500 for Ethernet. Check that your network interfaces are negotiating at the correct speed and full duplex.
You can monitor and adjust all of this through your router GUI.
To make troubleshooting faster, you can install a wire-speed switch to take the handoff from the carrier.
Each device (Router1, Router2, and Laptop1) should use its own IP address. This won't work if you only got one IP address assigned.
Where my carriers' Cienas handoff to us, we have Layer2 or Layer3 switches accepting the handoff into an isolated VLAN, not straight into a router.
Your MTU should be set at 1500 for Ethernet. Check that your network interfaces are negotiating at the correct speed and full duplex.
You can monitor and adjust all of this through your router GUI.
To make troubleshooting faster, you can install a wire-speed switch to take the handoff from the carrier.
Each device (Router1, Router2, and Laptop1) should use its own IP address. This won't work if you only got one IP address assigned.
Where my carriers' Cienas handoff to us, we have Layer2 or Layer3 switches accepting the handoff into an isolated VLAN, not straight into a router.
Wifi is limited by the wifi reception and the wifi speed.
When you use a speed test tool, you presumably use the same site for reference.
What router is in use and their spec?
Feed into router? 10, 100, 1000 MB port?
Does this router include A firewall component, deep packet inspection ?
When you use a speed test tool, you presumably use the same site for reference.
What router is in use and their spec?
Feed into router? 10, 100, 1000 MB port?
Does this router include A firewall component, deep packet inspection ?
Retail routers often have a lower throughput. Note that the asus is likely functioning both as a router and a firewall..
Also you are comparing a wired connection throughput to a wireless
Connect the system directly into the asus and test the equivalent performance over a wired connection or is that the asus data throughput you saw when tested connecting via wire?
Yes, a retail/consumer router will perform at a lower level compared to a commercial/business product.
Also you are comparing a wired connection throughput to a wireless
Connect the system directly into the asus and test the equivalent performance over a wired connection or is that the asus data throughput you saw when tested connecting via wire?
Yes, a retail/consumer router will perform at a lower level compared to a commercial/business product.
usually these circuits are configured as 100 full duplex and not auto. so try that.
A router is always going to cause some sort of loss with overhead. Plus the numbers should decrease as more devices are connected to the network. That said, I would recommend you get a more business oriented unit like a Sonicwall, and access points.
Buying new gear is not a solution. I have very old Sonicwalls that can carry more than 15Mbps. I have a Sophos UTM on P4 processor that pulls down over 100Mbps when all of the IDS and SSL interception is turned off.
You need to find the root of the problem first.
Did you check the MTU setting? An Ethernet handoff from a Ciena carrier switch is 1500 bytes. A firewall/router expecting a DSL or cable modem will be using 1492 or less by default.
Check with the service provider on frame size.
Turn off all inspection and intrusion detection on your firewall.
You need to find the root of the problem first.
Did you check the MTU setting? An Ethernet handoff from a Ciena carrier switch is 1500 bytes. A firewall/router expecting a DSL or cable modem will be using 1492 or less by default.
Check with the service provider on frame size.
Turn off all inspection and intrusion detection on your firewall.
When I rolled out ATT MPLS to 80 locations, we found that each location that had this CIENA box required our CISCO Router or Ethernet Switch that is connected directly to be configured with 100 FULL Duplex and NOT Auto!!!! So I will repeat has the OP checked this, ie is the CIENA box configured to expected 100 FULL Duplex, and is the Router/Switch configured to match! One should never assume the configuration.
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http://kb.netgear.com/19863/Ping-Test-to-determine-Optimal-MTU-Size-on-Router