Hey all,

I just posted a blog article about whether Your Internet is Suitable for VoIP. Check it out and let me know what you think

For a beginner or novice its a good beginning.

A good internet connection is an absolute necessity, obviously.

Not enough attention gets paid to network infrastructure INSIDE the building, though. It's really a must to have managed switches, not the $49 box from the big box stores to manage and properly route network traffic, with special attention given to voice traffic with VLANs created when necessary. Our salespeople learned this lesson the hard way after selling hosted VoIP to Mom and Pops with simple 4 port dumb switches. Unhappy customers always crow louder and longer than happy ones do.

Thanks for looking guys

JBean - you are correct about cheap consumer grade switches and routers, they can definitely burn you sometimes. However, some of the "big guys" like Ring Central like to blame call quality issues on the LAN. They say you NEED to have QOS implemented which is something beyond the average IT guys, let alone the average small business person. In practice, call quality issues 9 times out of 10 are completely ISP related.

That being said, call completion problems or 1 way audio most often have to do with mis-configured local equipment.

I'm in a unique spot. My company is the local CO, a hosted provider, an IT management company AND the ISP. Most of the time, call quality issues are my fault one way or the other, unless I can prove the problem lies outside my network.

The biggest problem we see with other people's networks is LAN settings that don't disable SIP ALG or allowing the port re-mapping tendencies of some firewalls.

Very true, mis-behaving routers can result in hair loss! I've personally observed Sonicwall routers randomly change NAT port numbers part way into a call - this obviously broke audio. Mind you, that was 10 years ago.

Which routers have you seen mess around with port re-mapping?

I prefer to keep the firewall name under my hat ( its initials are 'Sonicwall'). It still happens, but mostly because the customer's IT person isn't aware of the settings to stop it.

I dumped using Sonicwalls years ago. Man they gave me head aches.

Former employer used to sell Soincwall...until we stopped selling on premise phone systems and went to hosted systems. They were a nightmare for VoIP. Even when everything was configured the way it was supposed to be, even with SIP ALG turned off, things tended to break. Sonicwall would suggest a firmware update, requiring after hours work to bring down the customer's network, meanwhile they think we've sold them a dud of a phone system. Support was horrible, and it was clear the sale to Dell and back again was rough on them. We dropped Sonicwall and went with Fortinet. Didn't have a single firewall related voice issue between when we switched to selling Fortinet and when I left the company.

My challenge recently has been a side customer I have (my current position is entirely internal working on Avaya Aura and managing an IT service group) that isn't large enough to justify a more expensive firewall, so they rely on their AT&T provided "residential" gateway. It has been nothing but problems. Currently working through an issue with it causing their SIP trunks to drop registration a couple times a month.

I've been pleased with mikrotik routers on a 4 location vpn project I recently completed. Mikrotik are very feature rich and reasonably priced. There is a learning curve and I am still learning.

SIG ALG and consumer-grade routers tend to be more problematic. More than once I have had to troubleshoot a VoIP system connected to a Nighthawk router. These also tend to have SIP ALG on by default. I had to factory reset the last one for the phones to work. Other times I had to power cycle them.

A handy tool to detect SIP ALG:
http://mcstest.visualware.com/myspeed/myvoiph5_g711_sipalg.html

IMHO, I think you need to get Internet speed out of the customer's head when talking about VoIP. I have not seen issues related to the Internet bandwidth in a long time It is always the Quality of Service. When the Internet speed becomes an issue is when they are doing heavy uploading, such as cloud backups. The upload speed is almost always slower.

I have seen new problems arise after the customer upgrades their internet speeds. I had one user repeatedly tell me that he should have plenty of bandwidth because he just upgraded his internet speeds. All the issues happened after the speed upgrade. VoIP was working just fine on the slower speeds.

Another customer had a Unifi USG router. Issues after the Internet upgrade, in this case, were likely due to the router bottleneck. I disabled all the extra features, like intrusion detection. That fixed their problems. The router did not have enough throughput to handle the faster Internet speeds with all the security options enabled. A lot of these business routers have a throughput of about 300-500 Mbps when you start to enable extra AV or other security features.

Packet loss is the real killer of VoIP.

This is another nice tool to visually show the customer the ISP issues:
https://www.pingplotter.com/

Cyber Security is a major issue today.. I'd be very careful about what you disable.

This is why out of the box I normally turn on all security features that come with the security appliance (if licensed). You just have to be aware of limitations and potential bottlenecks that can be created with these additional security features,

The Ubiquiti USG at a customer location, that I mentioned was getting tons of dropped packets and very poor audio. If you look at the link below, you see that the USG throughput drops from up to about 900 Mbps with IPS disabled, down to only 80 Mbps with it enabled.

https://community.ui.com/questions/...ass/5f2d6a32-7d90-4168-9407-a5dd02980c4e

When I disabled IPS, no more dropped packets and the audio was fine.
The VoIP phone service had been working fine for a couple of years until the customer upgraded their Internet speeds.