Mitel 3300 MCD - Teleworker Problems with Draytek 2830

[bhhjor]

Hi,

Looking for some assistance with our Mitel 3300 MCD.

We recently moved to a new ISP and were provided with a new Draytek 2830.

Everything is now up and running except for our Teleworker phones at remote sites.  When I say not working that is not strictly accurate.  You can phone from the teleworker phone, the user (internally or externally) can hear you but you cannot hear them.  I've read articles on one way audio but they tend to be SIP issues.

I've been trying to get responses from Draytek as BT (Provider of the Mitel) say everything is working.

I'm a bit of a novice with routers but from what I've read it looks like firewall ports not being opened - I'm fairly sure they are.

All advice welcome.

Thanks

[ralph]

It's going to be a firewall issue.

Here's how.
When a call from a TW phone is set up, the phone talks to the 3300.
Once the call is answered, the 3300 drops out of the conversation and all UDP traffic is routed directly between the TW Server and the phone.
That's why the phone will ring and can be answered but has either one way audio or no audio.

So what's happening I suspect is that your firewall is allowing anything out (assumes the TW phone can hear the other end) but does not allow the TW server to talk to anything other than the 3300.

I think once the FW is configured to allow the TW server to talk to anything on your voice network the problem will be solved.

Ralph

[bhhjor]

Hi Ralph

Thanks for the response.

we have a 10.0.0.x network and the TW server sits on the network - no seperate Voice network.

The Draytek has a ranger of IP addresses and we use one as an alias to NAT across.

In the FW (Default Call Filter) we have set a filter rule for TW Server to point to the NAT address and to Pass everything.

Thanks

[ralph]

Which side is not hearing the audio?

How is your TW server configured?  Server GW mode, lan mode?  DMZ mode?

Another thing to try would be to ping a phone from the TW server to be sure that's open and then you can do the reverse of that from a phone.

There is a tool you can DL from the TW server called TNA.   Load it up on your network and point it to the TW server to see what ports are open/closed.

Ralph

[bhhjor]

The audio is working on the caller to the Teleworker.  There is no Audio on the Teleworker phone.

TW is in Server Gateway mode.

Will try the ping test.

The TNA has been downloaded.  The Load test works as does the Connectivity Test. How do you check the ports open/closed?

Thanks

[x-man]

2830 needs SIP Alog turned off and it can only be done in the command line.


Telnet in and apply these settings

sys sip_alg 0

sys commit. 

[bhhjor]

Checked SIP and it is turned off - I rechecked and rebooted.

Pings from both ends are fine and responding.  Still only one-way audio/

Anything else I can check?

Thanks

[x-man]

What level of software on the 2830?

[bhhjor]

Model Name  : Vigor2830
Firmware Version  : 3.6.8_sb_2471201
Build Date/Time  : Jan 20 2015 18:24:13

[x-man]

telnet in and do: sys sip_alg ? 

What does it report.

[bhhjor]

current SIP ALG is disabled.

[x-man]

OK thats ruled that out then.

What settings are showing in the 2830 for NAT My 2830 has no ports opened explicitly for teleworker but it works fine. I use an IP routed subnet here. I have details of setup if you need them.

I wonder if its the way the Draytek is configured for routing the external Ip address. I remember having issues  with one way that it was configured...

What has the remote worker got for internet access and has he got SIP Alg disabled?

[bhhjor]

I'll need to check the remote site and get back to you.

the NAT Open ports - we setup the Ports recommended by Mitel with the WAN Alias pointing directly to the TW Server.

Comment 
WAN Interface ALLWAN1WAN2WAN3
WAN IP xx.xx.xx.101
Local Computer    10.0.0.xx

--------------------------------------------------------------------------------
 Protocol Start Port End Port  Protocol Start Port End Port
1. -----TCP  22 22  2. -----UDP   69 69
3. -----TCP 443 443    4. -----TCP 3998 3999
5. -----TCP 6800 6803   6. -----TCP 6880 6880
7. -----UDP 1024 65535   8. -----UDP 20000 23000
9. -----TCP/UDP 35000 37000  10. -----TCP/UDP    2114 2116

I thought you needed to open the ports on the WAN side to go directly to the Server IP (or that's how I read them)

There are Firewall Filter Rules for the Default Call Filter where I've tried to add the specific UDP ports that are mentioned in the searches about one-way audio for Mitel.

[x-man]

Like I said I use IP routed subnet which was suggested by Draytek. It works fine but uses two external IP addresses which bothers me not one jot. No ports need to be opened but you do need to stop remote access to the draytek in management under ip routed.

[bhhjor]

Yes I understand and see how this could work.

One question - the TW server is on the 10.0.0.x LAN.  Do I need to change it to one of the spare Public IP addresses?

The next point will be remembering how to do this