FTTH users complain of slow speed

RouterOS General
1

Hello

We have a CCR2116 as BNG and FTTH clients (PPPOE or DHCP) complain that their download speeds when on wifi is 170Mbps but upload speed is full speed of the link. They get almost 100% of line speed when they test to IPv6 speedtest servers.

For eg 400Mbps client will get 170Mbps download and 390Mbps upload when on WiFi at their home. When they do similar tests using a network that uses Cisco they get well over 300Mbps download and upload on the exact same wifi routers.

When they are on cable they will get full download and upload speed. Router is currently on 7.14. L2 MTU on all interfaces is 9000, l3 MTU is 1500 and PPP setting on the BNG has Max MTU set to 1500, Max MRU as 1500 and Change TCP MSS set to yes

To rule out any internet congestion, I connected a speedtest server directly onto the BNG and get the same speed.

Has anybody else had this problem before / are there any suggestions I can try.

2

“When they are on cable they will get full download and upload speed” Does this mean when they connect a device via ethernet cable?

3

when on wifi

Question is what wifi ? AFAIK CCR216 has no wifi built in.

So there is the path to the AP, then the AP wifi. What AP or wifi is used here? WLAN or Wifi driver ?
WLAN driver can have more than 50% idle time, between transmissions, even if WLAN max MPDU (± 3900bytes) is used
Wifi and other brand drivers use much larger aggregated transmission packets. Check values for A-MSDU/MPDU and A-MPDU sizes.
http://forum.mikrotik.com/t/help-mikrotik-capsman-wireless-download-speed-max-200mb-but-pcs-mobiles-link-speed-is-866mbps/142677/1

Then 170Mbps on 400Mbps interface rate is normal for WLAN transmissions
For upload it is the client device wifi that defines the transmissions.

4

IMO - in general

  • When customers get their full upload speeds but do not get their full download speeds , then often the problem is the ISP’s upstream Internet connection is saturated and/or the ISP’s internal router/switch network is saturated.
  • The issue could be ; the ISP’s upstream internet connection might need to be upgraded to a faster connection.
  • The issue could be ; the ISP’s internal routers and/or bandwidth management devices are CPU and/or I/O saturated.
  • The issue could be ; the ISP’s switches are running at near saturation. Faster switches should be considered.
  • The issue could be ; the ISP’s transports to customers are running at near saturation.

There is always a solution when customer download or upload speeds do not meet measured speed tests that match the speeds the customer is purchasing.

In your case some questions come up:

  • how fast is the ISP’s internet connection supposed to be ?
  • is the ISP’s internet connection sustained bandwidth over 50 percent of the ISP’s purchased speed ?
  • is the ISP’s upstream provider overbooked ?
  • is the speed issue always there or only during normal busy peak hours ?
  • how fast is the ISP’s connection to their customers & are those links to customers overbooked ?

EDIT - added a note: When customers are not getting their full download/upload speeds , perform some traceroutes out to the Internet and look at those traceroutes for anything that is greater than 10 ms , then work at those hops. (( FYI - most of my customer traceroutes to the Internet are almost always less than 3 ms ( from customer through my networks to the Internet ), then at the Internet feed continuing out less than 10 ms to most Internet sites per hop.