2
There's already a post about this, but the solution to that one didn't work for me, so here's my version: We have Cox cable internet, 100mbps | We have a Sonicwall TZ 215w | We have a netgear L2 managed switch
We have four users
We have issues:
Internet bandwidth (browsing, ping) behind the switch has always been slow, 20% of rated speed.
Lately the VOIP phones have stopped connecting to the Vonage service. One, then two, then all in the space of about an hour. No external event corresponds; they unplugged one phone, then plugged it back in to the same jack.
We have been extensively troubleshooting and swapping boxes as such:
cablemodem <-cat5 direct-> computer = fast (full rated speed)
cablemodem <--> sonicwall <--> computer = fast
cablemodem <--> sonicwall <--> switch <--> computer = slow (20% rated speed)
cablemodem <--> switch <--> computer = slow
So the switch would appear to be the problem. However, we tried a different model netgear l2 managed switch, same outcome. We tried a dumb switch, same outcome.
Settings on all devices have been tried. Everbody has full duplex 100mbps (1000mbps on the gigabit switch). Sonicwall settings are verified correct for VOIP.
cablemodem <--> VOIP phone = good
cablemodem <--> sonicwall <--> VOIP phone = no good
cablemodem <--> switch <--> VOIP phone = no good
cablemodem <--> sonicwall <--> switch <--> VOIP phone = no good
But here's the kicker: We swapped out the Sonicwall for a Cisco firewall and then:
cablemodem <--> cisco <--> VOIP phones = good
cablemodem <--> cisco <--> computer = zero, can't get out (I didn't do this test, can't vouch for cisco settings)
It just doesn't add up. Does anyone have any suggestions what might be wrong and/or a solution? Netgear, Cox, and Vonage came up empty, repeatedly.... Thanks!
Uncle Frank
Posted 2015-05-06T06:28:29.210
Reputation: 21
Are you sure there is no ethernet loop? I would watch switch traffic counters, look for high traffic or excessive broadcasts – Dan – 2015-05-06T08:48:24.727
Good idea, I'll look into that. My sonicwall doesn't show anything like that, and some of our tests cut the switch out of the picture completely. And the speedtest numbers coming out of the cable modem fluctuate too, though always faster than the Sonicwall (except for yesterday when a couple of the phones worked and the sonicwall was putting out full cable bandwidth).Thanks! – Uncle Frank – 2015-05-06T23:43:05.587
The answer appears to be duplexing. The sonicwall, set to autonegotiate, showed 100m half duplex. When client had another guy plug in a cisco router and he set it to 100m full duplex, all problems went away instantly. Client not very happy with me..... – Uncle Frank – 2015-05-08T18:45:06.323