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Hot Desking and Shared Lines

Occasional Visitor

Hot Desking and Shared Lines

Let's say I have a desk phone and a conference phone in my office that I want to have the same extension and keep state information (idle, hold, busy) between the two phones.  But as an installer I want to setup the office phones quickly by simply creating my extension-phone cfg files and use hot-desking and have users login to their phones.


Is it possible to login to my two shared line phones using the same extension?


I've experimented and I've noticed that I can login to a shared line type however, the document, "Feature Profile 60688 Making Phone Settings Portable with User Profiles" advises against multiple same-user login.  Is this only advised against private line types or will this multple login actually work for shared lines?

Message 1 of 3
Valued Contributor

Re: Hot Desking and Shared Lines

I realize that this is an old question, but I figure it deserves an answer anyway, just in case someone else with the same question comes searching for one later.


The document that you reference doesn't really go into detail about why having multiple phones logged into the same profile is not supported by Polycom and not recommended, but I can hypothesize:


1) If your provisioning server allows for phones to upload changes made to the local configuration back to the server, then having two phones logged into the same user profile can cause conflicts and would not operate the way that perhaps most users would expect them to behave (e.g., if you make a settings change on one phone while logged into your profile, would you not expect another phone logged into the same profile to reflect that change? also, if you make one configuration change on one phone, and then a different configuration change on another phone, the second phone will likely wipe out the first change that the first phone pushed back to the provisioning server).


2) Many SIP proxies allow for SIP "call forking", where multiple endpoints can be registered to a SIP proxy simultaneously using the same credentials, and if an INVITE arrives for that user, the proxy will send one INVITE to every endpoint registered for that user.  Unfortunately, not all SIP registrars support this.  One very prominent example of a platform that does not support this is Asterisk.  If you register a second SIP endpoint to an Asterisk server using the same username as an endpoint that is already registered, then the newer registration will overwrite the older one in the Asterisk SIP peers table.  The last registrant for a given extension "wins", and only one endpoint will be INVITEd when a call comes in for that extension.  Since not all platforms can be guaranteed to do call forking at the SIP level, it would be a headache to try to support such a configuration.


Unfortunately for all of us, even though having multiple phones logged into the same user profile is not supported, there is also nothing in place to prevent it, either.  So it is entirely possible for somebody to log two phones into their profile simultaneously by accident (forgetting to log out of the first one), and thus to cause some of the issues referenced above to happen anyway.  It would be nice if there were some kind of feature to prevent more than one login, but in Polycom's defense, I'm really not even sure how such a feature would work or how it could be implemented in a clean and portable way.


-- Nathan

Message 2 of 3
Polycom Employee & Community Manager

Re: Hot Desking and Shared Lines

Hello Eng,

welcome to the Polycom Community and thanks to Nathan answering this post as well.


To answer this question you will need to take a look at the complete design.


In an old traditional PABX the phones itself held no intelligence and everything was controlled and managed centrally.


With SIP the endpoint is quite powerful as some may want to use a single line provider.


Using open source SIP server like Asterisk can only every use the feature rich functionality of our phones to the level the community is willing to add into Asterisk itself.


For example the apps.telNotification.lineRegistrationEvent could be used to communicate a registration change to a back end that holds a table and compares the prior state.


There is even a apps.telNotification.userLogInOutEvent already available.


If the users cannot be trusted to log themselves out the prov.login.automaticLogout can do this for them after a defined period.


Also the HTTP PUSH functionality described => here <= in detail may be useful.


We, Polycom, can only ever make our phones as versatile as possible but it is up to the individual end user to chose what part of the offer they want to use.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. My official "day" Job is 3rd Level support at Poly but I am unable to provide official support via the community.


Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 3 of 3