VPN Issues with Softphone why does softphone work better off the vpn and can I reroute my traffic so softphone goes outside of vpn on one computer

Member_2_4942450 used Ask the Experts™
Ok I work from home.

I have a softphone app called a mitel 8602 inter-tel software.

What I have discovered over weeks of working on an issue and with lack of real help from my employeer. There tech tech department seemed almost useless.

I have discovered the issue is now on them.

I am unable to use my softphone when I have the Cisco VPN client running.
It seems the min i turn my Cisco on the soft phone starts to jack up and calls come in with dead air or in the middle of a conversation I all of a sudden hear them but they don't hear me.

I have done numerious things from different ISP to even different locations and different computers. But each thing I've done goes back to the fact that when the VPN is on the phone doesn't work right no mater what ISP or what computer I am using.

I would like to find an answer as to why this is happening. It use to work. When I first started it working for the company it worked fine perfect. Not until the past 3 weeks have i had this issue.

So what I've been resorted in doing is keeping one computer with the Cisco VPN client on and do all my work from that computer and the other computer just nothing but the softphone app.

Can anyone explain as to why this is happening? its not like its my equipment because i've tried friends houses other businesses startbucks even different computers.

Also anyone have an idea where I could seperate out the traffic maybe on my system so that I can have the softphone and vpn client running on the same computer and maybe route the softphone date way from the vpn. Maybe could I split it so the only the softphone gets its only routing without vpn.
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
The problem is due to the way in which the SIP protocol works.
When a call is established the audio (RDP packets) is sent directly between the two endpoints (the office switch and your software client) and the SIP protocol tells each end the IP address and port number to which the voice traffic is to be sent. The problem occurs when one or both ends is behind a firewall. SIP tells the other end to send the traffic to your own local IP address on your private network and not the IP address of your router on the internet so it can forward the reply.
There are protocols you can run to avoid this problem such as configuring the client to use a STUN proxy server. However as your issue is that other people cannot hear you this means it is your outrgoing traffic which is not reaching the office and this would be due to a configuration error on the equipment at the office.
The reason why it works when you have the VPN client open is that in this case there is no network address translation going on and so when you get told to send the voice to the local IP address of the office equipment this is accessible.


The reason why it works when you have the VPN client open is that in this case there is no network address translation going on and so when you get told to send the voice to the local IP address of the office equipment this is accessible.

Do you mean the reason why it works when my vpn client is closed? I have to run the softphone on a seperate laptop WITHOUT the vpn running. and do my work on the other laptop with the vpn on.

Greate Answer. Love it. Very nice explination. Now how can I make just my sofphone app work and make sure it can route the sofphone app without the vpn on the same computer. or is that impossiable.

The reason why I am saying this is that the companys IT department with whom I am working for has yet to find a solution to fix this issue. They ened up resorting to giving me a physical brick phone. As a backup just incase Yuck. I sorta like the softphone.

Also I have noticed at times the soft phone messes up even without the vpn on? what could explain this.
Any ideas what I can maybe relay and tell them on what to do to fix.

Today I just started my shift and the softphone without vpn is already starting to mess up but for the last week it was working fine when I would keep it off the vpn.

Humm may have to use the brick phone and see what happens.

Any further info you can give me on this would greatly be appreciated. Nice answer so far grblades


The problem occurs when one or both ends is behind a firewall.
I have no firewall running so it must be them. Anything I can check in my linksys device to make sure.
C++ 11 Fundamentals

This course will introduce you to C++ 11 and teach you about syntax fundamentals.


There are protocols you can run to avoid this problem such as configuring the client to use a STUN proxy server
How can I do this?
Sorry I got it the wrong way round. I thought it worked through the VPN but not otherwise.
Whats probably happening in this case is that the software client is configured to use a STUN server so that it can detect its actual public IP address and use that when it tells the other end which IP address the voice should be sent to. When the VPN is connected your client is probably talking to the telephone system over the VPN but telling it all replies should be sent to your actual public IP address which wont be via the VPN. This different flow of traffic causes the issues.

You do actually have a forewall at home. Your linksys device connects to the internet and gets a public IP address. It then routes the traffic through to your computer which will have a private IP address (192.168.1.x for example)  and the router will perforn Network Address Translation (NAT) to allow your traffic to go over the public internet. This all works fine for outbound traffic but if you want to accept connections to your machine originated from the internet you need to add port forwarding on the router. This is where one problem lies in that inbound audio is considered a new connection. Using STUN helps avoid this as it tricks the router and starts sending out traffic when a call is established which makes the router think the incoming audio is a reply so it know how to pass it back through NAT to your machine.


I have NAT turned off. and the weird thing is that this only started happening in the past two weeks and since then nothing on my router has changed.

I don't have port forwarding setup at all on my router never used it.

How would I use STUN proxy server?

OH FYI this is now happening to the softphone non on the vpn today. They must be having issue. going to see if brick phone does it hopefully soon when I can see if they will change me over.

Trying to eliminate any possibility from it happening my end.
Using STUN is a common thing to do but its a one for all solution. The client is either enabled or disabled and its often an advanced configuration setting to change it. So normally your client would have STUN configured to be on and would work fine.
When you are running a VPN on the server you would normally configure a feature called split-tunnel (thats actually what Cisco call it) and the idea of this is that only traffic destined for your companies internal network goes via the VPN and all other traffic goes out of your internet connection. The connection to the office telephone system would therefore be excluded from the split-tunnel so that even when you have an active VPN connection none of the voip traffic is going over the VPN.

If you do that then it should get most things working but its something done on the server side so your IT department would have to configure it on the Cisco VPN server.
You mentioned that sometimes you had problems even when the VPN was not active. I am not sure about that as there can be a few causes but the first step is to fix the VPN issue I believe.
To use a STUN server you normally enable the option on the softphone and tell it an address of the server to use. This information would have to be provided by your IT department and may be something hard coded into the phone settings.


Experienceing problems today with it .. I will update you on status soon when I can figure out whats going on at the moment. They just sent a broadcast on the instant messenger that they are experiencing lag.

LOL jacked up company lol


Why does this even happen when I try multiple ISP and multiple locations like my friends and my friends busineses. Isn't this have to be an issue on there end?
Well the VPN issue has to be something wrong with the configuring at the companies end.
If they dont know how to fix it then I cant be confident on them being able to fix any voip issues as its a lot more complex topic than VPN.


LOL. Nice
Bad start to the day lets see how the rest of the day pans out LOL i will keep you posted.

Taking ghost calls right now lol. One call I actually had audio then it went back to ghost calls.


I just wanted to add this to the conversation

First part is an email we were sent about the company's VPN.

Here is a suggestion from our IT team about VPN's.

Agents should definitely have both VPN concentrators configured in their client software, both asa.*******.com and asasm.*******.com. This will enable them to quickly switch between concentrators should they encounter difficulty.

In regards to which concentrator reps should use on a regular basis, here are my recommended guidelines:
Agents working remotely inside Texas who are South or West of Austin should be encouraged to use asasm.*******.com. All other agents in Texas should be encouraged to use asa.*******.com
Agents working remotely in other parts of the country should be advised as follows:
West of Texas (and "the midwest") (AZ,CO,KS,UT,WA) should be encouraged to connect to asasm.*******.com
East of Texas (FL,IL,NC,SC,TN) should be encouraged to connect to asa.*******.com

My email to them
Internet Status And Summary of Results

After careful studying over the past two weeks I have come to the conclusion that partly the issue going on is a result of ISP (Comcast outage) and actual soft phone issues. After careful troubleshooting and trying different things here is what I found out.

PROBLEM EXPERIENCE WITH SOFT PHONE - Calls would come in and either two things would happen. Dead silence. They could not hear me and I could not hear them dead air or this would happen. I would be 1/2 though tsing with a customer and I would hear a call waiting type of tone. Then right after that I would be able to hear them and they would not be able to hear me. I would attempt to cal them back and experience either not being able to reach them like the call would not connect or it would connect and I would hear dead air. Today after speaking with your system admin the issue has seemed to get better I would hear the call waiting tone (which sometimes displays insufficient band width - keep in mine all my connections to the internet have been at 20 or greater down and 5 or greater on the up) but this time the call would stay good. I could still be able to hear the customer. So maybe he fixed it. We will see tomorrow after a full day. 

1. My equipment is not a part of the issue.
     Reasons Behind this.
     a) I have tested multiple OS and multiple computer systems all showed the same results when it came to soft phone problems
     b) I have even replaced cables and cords fittings and modem. Neither modem nor personal cables were the issue even after testing modem at friends house in several locations with both the new and old modem I bought using a hard wire connection.

2. ISP
     a) I have had a total of 5 techs out to the house.
     b) Techs did see issues and repaired them. Some techs had to submit reports to line maintenance to repair line work.
     c) Final tech came out today and it was a supervisor tech saw nothing wrong currently but did say it may be an issue that is hard to trace and will monitor my lines.
     d) I even tested a neighbors internet cable and both DSL service both having same issues when it came to using the soft phone 
     e) I even went to a few friends houses both either using Comcast cable for there provider or AT&T DSL also my wife's dads business. At each location I experienced the same issue with the soft phones

3. What I have done as well
     a) have reinstalled network drives
     b) replaced network cards (the cards were good and replacing them did not do anything)
     c) Reinstalled Soft phone several times on different os and different computers and laptops

4. Backup ISP
      a) I have also gotten a backup ISP 
      b) I do not think its ISP related now because test have showed the same results and problems with the soft phone when I went to multiple locations trying to get the soft phone to work.


Great job I would like further feedback on this as I post updates. Thanks
No problem I will leave myself monitoring this question so I get notified whenever you post an update.


did you see  my recent post what do you think???


Have I covered my steps on my end
It's getting late in the uk. I will read it properly tomorrow and give a reply then.


UK would love to work there Florida here


UK would love to work there Florida here
Finde me at user name messenger
Your update looks good. It is strange to hear a call waiting type tone midway during a call but its certainly possible.

It might be a good idea to ask what protocol is being used for the voice call.
I have assumed it is SIP as that is by far the most common with the exception of skype but it is possible they are using something different such as H323.

Do you know the name or IP address the voip client connects to?
If you do then you can download some free software called winmtr which you can set off pinging the remote destination that you connect to with the voip client.
If you get problems with the call then you should see winmtr reporting some packets being dropped.

Most problems with calls only effect the call being established. The most common problem is no audio in one or both directions. Its very rare to loose audio mid call unless the internet goes down or the telephone system crashes for example.


I don't think they are using sip but will have to check if they were using sip I could easy configure another client software

All they have me do is put the remotes ip and device ID in
It's a MITTEL softphone 6803 I think is the program name
Mitel can either use their own MINET protocol or SIP. Using their own protocol will give lots of extra features and in theory should have fewer problems as SIP is really not very well designed. However if the company can enable SIP for you it might be worth just giving it a go anyway.
Hi  my name is mandygurl and I work from home as well my story is similar to this story almost identical but my calls are dropping every time I receive a call it rings once and hang up and the phone goes blank. Then I have to restart the soft phone to be able to receive calls. Ive tried everything the IT guys at my place of business is also stumped on the situation.. Could u please help what do I need to do to resolve issue.

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial