EHDU over SIP

[TTRev]

Hi,
Relatively new to Mitel 3300's (although plenty of experience with other PBX's over the years) and I am trying to setup EHDU. The goal is to replicate some functionality currently on one of our legacy systems where an external team would publish one number and then when a new team member would come on shift they would dial in to the PBX and remotely change the divert on the published number to their own mobile.
It looks like EHDU would fit this purpose (I have been told to stay away from DISA because of security concerns?)
I should mention at this point that we have clustered 3300's and external calls are via SIP trunks to Audiocodes SBC's and then out to a third-party SIP provider. We do have an MBG but we only use it for Teleworking and do not route normal calls through it.

I have followed the help file and performed the following steps

1. Enabled EHDU License on the MCD
2. Created a new hotdesk extension
3. Given it a COS that includes the EHDU features (as far as I can tell)
4. Ticked External Hot Desking Enabled
5. Put in a Dialing Prefix (9)
6. Set a PIN
7. Used one of our spare DDI numbers to setup a Hot Desking Access number

I can call the Access number and I get ringing then dialtone
I then enter the 5 digit extension number at which point I get dialtone again
I then enter the 6 digit PIN followed by #
The call then immediately cuts off
This of course means that I cant attempt to change the number that it points to

If I use the command LOCATE FEATURE EXTENSION <number> then I get the following

Hot Desk : 32997 Login active externally at 9
IP Device ID: 1047
Circuit Location : 1 3 9 47 1
Extension : 32997
Active Features :
Service Level: Full
Zone ID: 1

Primary Element : LEID 101 - Routing Digits : 42000 *
Secondary Element: CEID 102 - Routing Digits : 43000

If I look in the Maintenance and Software logs the only relevant lines I can see are as follows

Log Type Software
Log Number 19316
Severity Warning
Date 2017/May/11
Time 14:55:28
Source Call Control - Software
Description FEATURE_ACTIVE: ehdu_inbound_a
Module Main
File Name and Line Number log_outputs_util_en.c;1224

Log Type Software
Log Number 19315
Severity Warning
Date 2017/May/11
Time 14:55:28
Source Call Control - Software
Description EXCEPTION digit receiver unavailable, OFFSET 2:$3086, PC: $357C16 LOG_ID: cpxceptn#30, PROCEDURE: process_exception, SEVERITY: cp_major PID: ($1, $A8) SWID: xnet_trunk 1682 PARTY: orig, STATE: dialing_party, DAM: busy
Module Main
File Name and Line Number log_outputs_util_en.c;1224

So it would seem that there is potentially nothing to register key presses (digit receiver unavailable) is this correct?
I have read some things about KPML and I have no idea if its supported by the Audiocodes SBC's or not (we are currently using RFC2833). I have also seen that you can somehow involve the MBG to help out but since it is not involved in the call path is that a no go?

Any help anyone can give me would be greatly appreciated.
Many thanks

 

[kwbMitel]

Thank you sooo much for providing the purpose behind your question.

Although EHDU likely would allow you to perform what you intend, I'm not sure that it is the easiest from a user / cost / support perspective.

My understanding is that you want an inbound call to be able to be terminated to an external mobile number on a flexible basis and initiated by the user.

A typical application of such would be a rotating on call schedule between several techs.

If my analysis is correct, I would likely be pointing you to Third Party Call Forwarding.



**********************************************
What's most important is that you realise ... There is no spoon.

 

[TTRev]

Apologies, been very busy so haven't had a chance to get back here until now. Thank you so much for your answer!

Would you be able to invoke the Third Party Call Forward from a random mobile phone however? Wouldn't it have to be a phone on the LAN or Teleworker?
They will not be onsite when they need to change the divert, they will probably be on the road or at home somewhere you see.

Cheers

 

[sarond]

I would double check your PIN.

I just tried it and it works for me. Although if I use an incorrect PIN I get disconnected.

You can confirm by logging in to a normal deskphone (assuming you have hotdesking setup)

I know I will probably get crucified for this but... I use DISA with Forced Account Codes sometimes to get dialtone from the system and then use Third Party Call Forwarding as kwbMitel mentions.

 

[TTRev]

I would love it to be that simple but I have tried logging in internally and it works fine. Just double-checked dialing the EHDU Access number again and still the same. Call disconnected after entering PIN then #.
I wouldn't be totally averse to using DISA if I could lock it down securely enough. What precautions do you take to ensure no 'hacking' if you dont mind?

 

[sarond]

DISA is similar in the way that you program a DDI in the System Access Points form (same place as Hotdesking Access) for DISA Forced Account Codes.

DO NOT USE DISA with out account codes, it will give a user dialtone with no verification.

Program an independant account code (this is used to verify access)
Program a COS to the account code accordingly (Allow third party call control etc...)
Then program a COR <-- This is where I would restrict the account code from any outside access.

Toll Fraud is the biggest concern but as with anything there is risk. Although the account code may not allow outside access it could potentially forward a DDI to an outside number and could be comprimised that way.

To be safe I restrict all International calls. Except maybe for the CEO if required.

 

[TTRev]

Cheers sarond. I will look into DISA and see if I can make it secure enough.

I would like to get EHDU working though if only as a technical excercise. Is there anyone out there that has experience at EHDU over SIP trunks?

 

[sarond]

My EHDU are over SIP trunks. Although mine are direct to the MCD, not via an SBC.

 

[TTRev]

Does your SIP trunk provider support KPML then or are you making it work in a different way? Cheers

 

[sarond]

No we are not using KPML.
If it is of any value it is Telstra Australia.

 

[TTRev]

Oh? I thought that EHDU required KPML for mid-call features!

 

[sarond]

Mid-call features are not used when dialing the access number and changing the EHDU destination.

Yes, pretty sure you need KPML for mid-call features, that's why mine doesn't work