3CX Web Client issues?

[3CXITS]

Hi All,

I’m experiencing a strange issue with the 3CX Web Client (Edge Extension) and I’m wondering if others have experienced the same?

The crux of the issue is below:

• Delayed answering of calls. Call will be answered, then there is a period of silence before either party can hear each other. This is usually around 10 seconds, by which point the caller often hangs up as they've not heard anyone - if the caller is patient enough, it will eventually connect. (not always though)
• Web Client Extension losing the ‘contact list’ and then reconnecting (this will drop calls if one is on-going)
• Issues are much more prevalent in core hours (between 11-4). Before those times the delay is still there, but not as great.

The issues DO NOT happen on the Windows Softphone or Smart phone Apps – just the Edge Extension. The Windows Client and Softphone clients (As far as I understand) seem to use port 5090 to tunnel back when 'out of the office'. The Web Client is possibly using the RTP ports?

The PBX is a cloud hosted PBX (behind a third party supported cloud firewall) the people using 3CX at home aren’t behind corporate firewalls etc.

I feel there could be many possibilities here and it’s a case of narrowing it down –

• Anti-Virus or protection apps installed on specific machines impacting Edge?
• General browser issues? People have multiple tabs open, could that be impacting the Edge extension performance?
• DNS TTL issues? (we use a 3cx FQDN). But that wouldn’t explain why the Windows client is unaffected.
• RTP Ports? I don't know how the firewall is configured on the PBX side as it's supported by a third party, but I've read a lot about the RTP ports impacting performance on the web apps (could that be an angle to ask our provider to check?)

As I said, the Windows softphone connected to the same PBX and running from the same environment (home internet connections/not behind corporate firewalls) is not experiencing the issues.

I’m hoping someone has seen similar before and may be able to give some suggestions/point me in the right direction based on my thoughts.

FYI – Version of the PBX is 16.0.6.655

Cheers,

 

[SteveITS]

Yes the web client uses the RTP ports. You can ask them if the 3CX firewall test is passing.
Does your issue happen in multiple locations? (i.e. at your home)

 

[3CXITS]

Yes the web client uses the RTP ports. You can ask them if the 3CX firewall test is passing.
Does your issue happen in multiple locations? (i.e. at your home)

Thanks for the reply - Yep, from multiple locations. Home, people in offices who use the web client, or people on third party networks who use the web client etc.

From what the provider have said the firewall test passed on the point of install, I'm not sure it has been run since. I'm wondering if they have expanded the range of ports allowed? (I read something that 3CX released an update a couple of years back allowing a bigger range of RTP ports).

I'm starting to believe it may be that, as like I said it's fine in the start of the day...but as it gets busier and teams start taking more and more calls the problems ramp up (all the RTP ports being used up?). I will go back and ask them if they wouldn't mind double checking the RTP side. I'm unaware if there is an internal firewall between the hosted box and the cloud gateway either, so I will ask that as well.

It seems to feel more firewall port related every day.

 

[StefanW]

Many things indicate also that the instance might be under spec. How many users do you have on the system connecting via the web client?

 

[3CXITS]

We've got about 3000 users on the system, I'd estimate at the very least 1500 of those using the web client. Spec wise, are you referring to the server hardware? It's on a cloud hosted box with 24G of RAM, 100MB link back out to the WWW. CPU averages around 10% during the day.

 

[Evolute IT]

At 3000 users, I think your bottleneck is probably the 100mbps link. You need more than that, specially since you handle 1500 Webclients.

How much CPU cores do you have?

 

[JohnS_3CX]

Specs for your size machine fall in the Enterprise+ Category:
https://www.3cx.com/docs/recommended-hardware-specifications-for-3cx/

 

[SweetAction]

Specs for your size machine fall in the Enterprise+ Category:
https://www.3cx.com/docs/recommended-hardware-specifications-for-3cx/

Typically I estimate 30KBps for each call when estimating needed WAN. What should I expect (from a WAN needs) for:

1) An idle extension with 40 BLFs - webclient/extension
2) An idle extension with 40 BLFs - windows/mac client
3) An active extension (single call) with 40 BLFs - webclient/extension
4) An idle extension on mobile app

 

[SteveITS]

An active extension (single call)

The call part will depend a lot on the codec: https://www.3cx.com/blog/docs/bandwidth-utilised-for-voip/

 

[SweetAction]

The call part will depend a lot on the codec: https://www.3cx.com/blog/docs/bandwidth-utilised-for-voip/

That's a great post.

I should have stated External calls I estimate at 30KBps, but I would love to know what 3CX wants for internal calls as well when going over WAN (i.e. not in same LAN or behind same SBC) since this is more common post COVID.