VoIP and Unmanaged Switch Incompatibility?

[Nimisys]

a quick question for the professionals out there, and my access to information is limited to make it worse.

I get to play IT guy for work a small business: 4 wired PCs, single printer, single credit card machine and 7 VoIP phones.

the 7 Phones go directly from the patch panel to a Cisco Catalyst 3750 PoE. 2 PCs go from the patch panel to an unmanaged Netgear gigabit switch #1. one PC, Printer, CC machine go to a separate unmanaged Netgear Gigabit Switch #2, then into the wall, out the Patch and into Netgear Switch #1. Final PC goes in to a Cisco Linksys e1200 router (dhcp disabled, assigned static IP, WAN port not used, serving as a switch and wireless AP only), then into the wall, out the patch and into Netgear switch #1. Netgear Switch #1 then goes into the CIsco Catalyst 3750, which is the sole DHCP provider and the gateway to the Mikrotec 2011iL-RM router that connects to the telecom via 5ghz fixed wireless on the roof. we are a mile from MCAS Miramar (as seen in the movie Top Gun).

we are getting an issue with the phones going into an idle state after 15 seconds, resulting in random dropped calls, short rings and on occasion out of synch rings (we are on a ring all strategy). Telco thinks it might be our equipment causing the issue (they are thinking some firewall software or internet filtering software - none of which beyond windows built-in, is being used) or related to switches being daisy chained. we have had ZERO network data issues out side of random internet slowdowns. PC-PC and PC-Printer performance has remained consistent.

Telco claims the VoIP phones are auto VLAN'd based off of MAC address, and they told us to plug into the Catalyst for internet and networking. Now they want our equipment removed from it (lol the single cat 6 cable), which results in no internet or email so we can see how the phones perform.

Now its been about a decade since my CCNA lapsed, but I honestly don't see how our simple little network should be causing QoS concerns for the phones. Being VLAN'd, outside of completely using up all available bandwidth and the QoS features of the Cisco switch notwithstanding, I don't see how any of our equipment could be causing an issue. our PCs get used primarily for email and web browsing. we have simple filemaker server and about 20gbs of photos that get occasionally accessed.

I have asked for, but not received a copy of the current config for both the Catalyst 3750 and the Mikrotec router.

so for those of you who actually know what the hell they are doing, any input?

 

[goodcooper]

hard to say, the issues with the phones are intermittent?

failure after 15 seconds sounded like a NAT issue... who/where are the voip phones connecting to? is this the provider you're mentioning?

 

[Vengance_01]

Why are you using so many switches. I would recommend plugging everything into the Cisco switch and and drop as many of ther unmanaged as possible. Also use vlans to separate the voip and other traffic

 

[Nimisys]

hard to say, the issues with the phones are intermittent?

failure after 15 seconds sounded like a NAT issue... who/where are the voip phones connecting to? is this the provider you're mentioning?

out of sych and short rings are intermittent, the 15 second and then standby is not. it manifests as the phones ringing 4.5 times and then going silent, but the person calling continues to hear what ever number of rings the queue is set for (35sec IIRC). the VoIP phones are Polycom VX400 series, and they go directly from the patch panel into CIsco 3750 Switch. Provider is a local small telecom (ztelco)

Why are you using so many switches. I would recommend plugging everything into the Cisco switch and and drop as many of ther unmanaged as possible. Also use vlans to separate the voip and other traffic

using multiple switches for two reasons. one the CIsco 3750 is 10/100 only. so one Switch is used to provide 10/100/1000 to the 3 patch panel data ports, the filemaker server and a future planned NAS. second, i only have 3 data drops to work with in the building, one of which has to serve a PC, a Printer and a CC machine. so thats one switch i can't get rid of. the final switch is actually being used as a wireless AP.

the phones and data are already supposed to be on separate vlans, but the telco will not share the config file in use for me to verify that.

on the plus side, i did take a 15 minute window today to power down everything, disconnect the data network from the Cisco 3750 and then retest it with just the phones, and i am getting the same 15sec failure. so hopefully this means they will move past our equipment being connected and actually start to diag whats going on.

 

[goodcooper]

out of sych and short rings are intermittent, the 15 second and then standby is not. it manifests as the phones ringing 4.5 times and then going silent, but the person calling continues to hear what ever number of rings the queue is set for (35sec IIRC). the VoIP phones are Polycom VX400 series, and they go directly from the patch panel into CIsco 3750 Switch. Provider is a local small telecom (ztelco)

and this same voip provider is the one providing the switch/router?

using multiple switches for two reasons. one the CIsco 3750 is 10/100 only. so one Switch is used to provide 10/100/1000 to the 3 patch panel data ports, the filemaker server and a future planned NAS. second, i only have 3 data drops to work with in the building, one of which has to serve a PC, a Printer and a CC machine. so thats one switch i can't get rid of. the final switch is actually being used as a wireless AP.

the phones and data are already supposed to be on separate vlans, but the telco will not share the config file in use for me to verify that.

well he's just going to say upgrade your poe switch to gigabit and run any additional drops where needed, but....

i doubt any of this is the problem... unless your switches are hooked up improperly (plugged into each other, i doubt they have STP on those consumer grade switches) or something.... i don't even think the separate voip vlan is a concern, it's certainly best practice, you only really need to go down that troubleshooting route if you find it's the QoS that's the problem... i.e. if you only have problems when your PCs are hooked up and downloading

also, if you're wondering, auto-vlan with common (or even pre-configured pre-fix) phone mac addresses is a feature on many switches... so that would certainly not be out of the realm of possibility...

on the plus side, i did take a 15 minute window today to power down everything, disconnect the data network from the Cisco 3750 and then retest it with just the phones, and i am getting the same 15sec failure. so hopefully this means they will move past our equipment being connected and actually start to diag whats going on.

and that's exactly what you have to do... rule stuff out to the satisfaction of your provider to prove to them they have to take action... 15 sec failure sounds like SIP/NAT issue, and if they're providing the mikrotik router there with the configs then that's on them... or they need to reconfigure their PBX... either way i'm not sure how they could possibly ignore this issue

 

[Nimisys]

and this same voip provider is the one providing the switch/router?

yes

well he's just going to say upgrade your poe switch to gigabit and run any additional drops where needed, but....

had I been the one purchasing equipment or planning the runs in the building, there would have been a data run at every phone drop as well as a gigabit PoE switch. However the telcom spec'd and provided the PoE Switch and the boss thought "we only use 3 PCs, so we only need 3 data drops", so that what we got. dropping more is not an option.

i doubt any of this is the problem... unless your switches are hooked up improperly (plugged into each other, i doubt they have STP on those consumer grade switches) or something....

I haven't found anything in their technical specs to indicate to what degree STP is utilized, and even then, none of them are setup in such a way I could get a loop either.

i don't even think the separate voip vlan is a concern, it's certainly best practice, you only really need to go down that troubleshooting route if you find it's the QoS that's the problem... i.e. if you only have problems when your PCs are hooked up and downloading

also, if you're wondering, auto-vlan with common (or even pre-configured pre-fix) phone mac addresses is a feature on many switches... so that would certainly not be out of the realm of possibility...


and that's exactly what you have to do... rule stuff out to the satisfaction of your provider to prove to them they have to take action... 15 sec failure sounds like SIP/NAT issue, and if they're providing the mikrotik router there with the configs then that's on them... or they need to reconfigure their PBX... either way i'm not sure how they could possibly ignore this issue

Problem is they have failed to mention how long they needed stuff disconnected for, as well as being the ones who insisted we connect directly into their equipment. I wanted to keep both networks physically separate just to be able to avoid this sort of problem. dealing with this stuff takes me away from my primary job, the one that I actually enjoy.

 

[goodcooper]

had I been the one purchasing equipment or planning the runs in the building, there would have been a data run at every phone drop as well as a gigabit PoE switch. However the telcom spec'd and provided the PoE Switch and the boss thought "we only use 3 PCs, so we only need 3 data drops", so that what we got. dropping more is not an option.

well there is always an option...

Problem is they have failed to mention how long they needed stuff disconnected for, as well as being the ones who insisted we connect directly into their equipment. I wanted to keep both networks physically separate just to be able to avoid this sort of problem. dealing with this stuff takes me away from my primary job, the one that I actually enjoy.

i would say that's a prudent course of action.... you shouldn't have to do it... but apart from switching providers or getting them to be responsive, you're kind of at their mercy

or... just find an IT guy to deal with them for you... offer joy rides for IT services

 

[JTKellyClark]

Sounds like the issue is on their end, especially as it is their equipment. I'm not surprised that they won't share any of the config info with you for their equipment, I've run into the same with most telcos (and small local telcos tend to be particularly touchy). I would guess that it is a NAT issue on the MicroTik router but there really isn't a way for you to diagnose the issue.

I'd suggest you inform them that the system does not work in the way they assured you it would, that it is not adequate for a business, it is costing your money and if they do not resolve the issue within [specify a time frame] you will be moving to a competitor. (all said in the most diplomatic way possible of course)

 

[stormy1]

The last time I ran into similar issues 3 people were listening to internet radio on the network and it was killing the switch with udp traffic when multiple voip phones were being used.
So my first step make sure no one is using streaming services and change the router wifi password to make sure you don't have unwanted guests.
Are you in the US? If so you need to consider pci when designing your network. Right now that you have would not be compliant.

 

[Deleted member 126051]

Sounds like the issue is on their end, especially as it is their equipment. I'm not surprised that they won't share any of the config info with you for their equipment, I've run into the same with most telcos (and small local telcos tend to be particularly touchy). I would guess that it is a NAT issue on the MicroTik router but there really isn't a way for you to diagnose the issue.

I'd suggest you inform them that the system does not work in the way they assured you it would, that it is not adequate for a business, it is costing your money and if they do not resolve the issue within [specify a time frame] you will be moving to a competitor. (all said in the most diplomatic way possible of course)

Bingo!

Them that pays, says.