Quality of Service (QoS)

[darrellchapman]

We have just purchased 3CX and plan to deploy it company-wide to replace our aging proprietary phone system. Since 3CX offers the VoIP client, we figured we could purchase our phones is several phases throughout the year (to limit our cash outlay). With that being said roughly 75% of the company will be using the 3CX VoIP client upon deployment.

Does anyone happen to know if the VoIP client implements QoS in the packets it delivers to the 3CX Server?
If not, does anyone know of a utility that can modify the packets being sent to inject the priority tags for QoS?

I'm not concerned about the bandwidth from our 3CX server to the Internet. That traffic can be shaped with our router. I'm more concerned about our LAN. We're all on Gigabit Ethernet and am really only concerned with closing time (when everyone is saving all of their data). I fear call quality will suffer during this.

Your help is greatly appreciated.

Darrell Chapman

 

[darrellchapman]

No one can answer this? Not even 3CX developers?

 

[jantoney]

BUMP.... 3CX please??

meanwhile - darrellchapman are you are 3cx partner?

If you are a partner you should consider using you partner tools to ask the question.
else i know that all the guys company wide are really gearing up to release V5.1 ASAP...
once that is out then just bump this back up to the top again!

EDIT:
Could a wireshark capture help you find the answer you are looking for?
http://www.wireshark.org/

 

[darrellchapman]

Sorry, I'm not a partner. I've just recently jumped on the VoIP bandwagon and purchased 3CX Enterprise for our business. Do you think submitting a trouble ticket via my support portal would help?

I didn't think to use wireshark for that. I did use it to successfully identify the source of my phone auto-provisioning problem. Thanks for the advice.

I'll look more in to it.

Thanks,
Darrell Chapman

 

[matthijsolislagers]

Take a look at this: http://bandwidthcontroller.com/

It is meant to controle internet traffic but you could use it for internal traffic. Just give SIP traffic a higher priority.

It is a cheep and easy solution.

 

[SY]

Hi Darrell,

VoIP client doesn't add DS/TOS mark for RTP packets.
Do you expect real benefits from this marking?

Thanks

 

[Fynskisb16]

Since you are running gigabit on your lan you shouldn't have issues. Is your file server on the same box as your 3cx? If it is you might see some degrade in service during peak times but its hard to say.

 

[asfuture]

Darrell, on a site from a client from me it was a LAN with HUBS. what do you think??? i had 4 phones (1 Etech, 3 Siemens) en 2 soft phones. all was acceptable. when i was there i said to the owner: i give you no guaranties that this system will work. but he wanted. en it was working with v3 from 3cx. now they have a normal 100Mb Lan with SW.... :lol:

 

[matthijsolislagers]

Hi Darrell,

VoIP client doesn't add DS/TOS mark for RTP packets.
Do you expect real benefits from this marking?

Thanks

Of course there are benefits. Especcialy for external extension I think. In that case routers can shape the VOIP traffic. For larger organisations it might also be interesting for internal usage.

For example: A school. All users log on and log off at the same time at the beginning and end of a lesson. At that moment the switches are very heavy loaded.

 

[asfuture]

Mathijs, i think that you are right. i don't know if that so difficult is. but maybe is a good point for the forum: features request.

 

[darrellchapman]

Sorry for my delay in getting back to this; for some reason I'm not receiving notifications that these posts have been replied to...

Anyway, yes I do expect to see a real benefit from using QoS. We're an engineering company and everyday users are checking out on average 1-2GB of data. This data is transferred to their computers so that they can work with it locally. The problem is that they all check their data in at (roughly) the same time which brings the network to a crawl with some segments using upwards of 97% of effective bandwidth for a given link. So yes, I'm a little concerned about calls being dropped internally.

If I was dealing with traditional VoIP phones, I could easily prioritize network traffic using the MAC addresses of each individual phone. This is not possible with the softphone since all data coming from it has the same MAC address and the NIC installed in the computer.

Externally this is not an issue since I can shape the traffic with my router to give priority to data on the ports being used by 3CX.

You're all right. This may not even be a problem given the amount of bandwidth a call actually uses combined with the fact that I've setup 3CX on it's own dedicated server. However, I convinced my boss VoIP was the way to go and if calls get dropped with the 3CX VoIP Client, we'll have to abandon the 3CX VoIP client. Not something I want to do.

The Bandwidth Controller suggested by matthijsolislagers may be the only viable option right now.

Thanks for everyone's input. I really do appreciate it.

 

[asfuture]

He Darrell
The bandwidth that you need:

G.711 (64 Kbps)
80 Bytes
10 ms
4.1
160 Bytes
20 ms
50
82.8 Kbps
67.6 Kbps
87.2 Kbps

G.729 (8 Kbps)
10 Bytes
10 ms
3.92
20 Bytes
20 ms
50
26.8 Kbps
11.6 Kbps
31.2 Kbps

for more information : http://www.cisco.com/warp/public/788/pkt-voice-general/bwidth_consume.html
I hope that this info are usefully.

 

[Fynskisb16]

Darell,
Speaking of your LAN, If the network is crawling during working hours then you do need to get some QoS on your network. You will need to get some type of managable switch that can allow access list to be created on it. You can priortize the RTP traffic from you softphones. Cisco has some low end switches that will work. If the QoS is set up correclty you can hammer the network and the voice calls will be fine. I like hardware over software when is come to bandwidth management also. Software (unless dedicated) seems to be flaky if running on a server that is used of other tasks.

 

[zensoftware]

Hi Darrell,

Not sure how easy this is to actually deploy but Microsoft do appear to give you QOS tagging per application on the client that can be deployed via Group policy on active directory.

(According to this article)

I have never tried this so please don’t ask me how to do it but I thought you may find the article of interest.

Cheers

Neil

 

[bluefox8080]

Darrell,

What switches are you using? Is the layer 2 or layer 3 managed switches?

If it is layer 3 then you can give priority to RTP packets on the switch (port 7000 - 7019 and 9000 - 9019).
If it is layer 2 then you can give priority to the physical port that the 3CX box is plugged in.

You can also create 2 VLANs, add the file server to VLAN1 and the 3CX server to VLAN2 and all the client PCs to both VLAN1 and VLAN2 (or if you prefer VLAN3 with Port 1 and 2 on the switch bridging all 3 VLANS)

Then give the highest priority to VLAN 2 (3CX's VLAN)

 

[asfuture]

he Darrell
i recommend you HP 26xx series or 16xx series. they are manageable en easy to configured.

 

[darrellchapman]

bluefox8080, we have layer 2 switches so I can't assign priorities based on ports, only mac addresses and physical ports. Since we are using the 3CX VoIP Client our layer 2 switches will do no good for us and can't afford to go buy all new layer 3 switches.

I'm hearing more and more about VLANs but don't have a firm grasp of what they actually are. Our switches do support VLANs though.

Thanks for everyone's help.

Darrell Chapman

 

[bluefox8080]

bluefox8080, we have layer 2 switches so I can't assign priorities based on ports, only mac addresses and physical ports. Since we are using the 3CX VoIP Client our layer 2 switches will do no good for us and can't afford to go buy all new layer 3 switches.

I'm hearing more and more about VLANs but don't have a firm grasp of what they actually are. Our switches do support VLANs though.

Thanks for everyone's help.

Darrell Chapman

Hi Darrell,
I meant physical port. That will work perfectly.
You have two sources/destinations of traffic: File sever and 3CX server
Just put your 3CX server on a high priority physical port and your file server on a low priority physical port. This should obviously be on the same physical switch.
It will have almost zero impact on your normal file server performance since the voice packets are so small

 

[darrellchapman]

Ah, brilliant. It sure is nice to have other people to bounce ideas off of. Thanks so much for your help.

Darrell Chapman