SLA and the need for assistant functions

I have been scanning the forums on this and really can’t find the answer to all my needs, of course.

I am setting up an office of 50 phones. The execs have 1 or more assistants who need to have access to their extensions. I need a way for the assistants phones (all Polycoms) to have a line that would ring when the boss’s extension is dialed. And for them to pick up that line when it rings. Basically, an SLA.

Groups won’t work because the line will ring the assistants line, not the boss’s line. So the assistant would not be able to tell which extension is ringing.

Same as with the follow me method.

I’ve gotten close with assigning an attendant.resource but that does not ring the phone.

I realize that FreePBX doesn’t support SLA but how are people accomplishing this? I can’t imagine executives handling all their phone calls?

Any ideas?


I simply put a second line appearance on the phone. That line appearance is part of a ring group that includes the phone of the “boss”.

Either user can then pickup the phone.

The ring group actually serves as the public extension.

Then there would be 2 extensions for every executive. So that if someone dials the executives real extension, this function will not work.

And if going by group only, if an assistant forwards the call to the executive, it will ring everyone again.

I don’t see how this work-around would work properly.

Putting the second line on the phone and using a Ring Group (or a Queue, which I like because of the ability to CID Prefix calls – but poses a problem with Find Me/Follow Me)works. To K9Sports comment, if someone 4-digit dialed the executive and the Ring Group or Queue didn’t work, that internal person would just have to know the phone system’s limitations and hang up and call the exec’s secretary directly. I am very interested in Asterisk 2.9’s SLA ability as detailed here Does anyone have much experience using Polycom IP phones using SLA?

The SLA module is for shared lines not extensions. It has many limitations and I don’t think it would solve your issue.

The only hope we have is this patch:

It needs to get ported to 1.8

The Polycom’s support Broadsoft style shared extensions.

Clearly this is uncharted waters so YMMV

Can you explain how the shared line works? I read the link I posted. Seems to me that if you want to use sla you don’t use an extension on your phone’s line appearance, rather you subscribe to a trunk that calls out disa?

Are you asking about Asterisk SLA or the the Broadsoft shared SIP extension I sent you the link to?

The Broadsoft patch allows phones that support Broadsoft shared extensions to subscribe to a SIP peer from more than one endpoint. Placing hold puts the call on hold on all registered extensions to that peer.

Asterisk SLA allows you to share a trunk (complicated with SIP, straight forward with DAHDI) and associate it with a peer. The peer can be most any channel technology.

I use Polycom IP phones. They support shared and private type of extensions defined in the reg.x.type. I resell a service based on a Metaswitch that performs the task nicely. If you choose “shared” on line.x.reg and program a line the same on another phone, when you put a call on hold you can pick it up on the other shared line. The shared line can also see when you are on that line. No need to use different ports for each line reg (5060, 5061, etc) on the phones with the Metaswitch. For example, on one IP550 you can put ext 1000, 1001, 1002, 1003 on line appearance 1, 2, 3, 4. Mirror this on another IP550 and you can monitor each line on both phones. (I assume you know this, just stating for clarity’s sake.) Move to the IP650/670 and use the sidecars and you can monitor something like 40 lines. If I could do the same thing on an Asterisk/FreePBX box it would be great. With Asterisk I think you need to use different ports on each line reg or you get funny results like calls randomly not ringing through. But is this what the Broadsoft patch does? Thanks.

You can monitor lines, you just can’t register them with Asterisk. They will show ring, in use and hold state. You can also use directed call pickup to pickup a ringing line. I also assign a BLF to park so the exec can park a call and the admin pick it up.

With the patch I posted (that I have not tried yet) you can register the same SIP peer to multiple extensions.

The Polycom’s claim to support the Broadsoft extensions so they should work.

This patch could be the first step in solving a lot of issues. Since Digium seems uninterested in SCA functionality, it looks like some smart folks are taking it on themselves.

I remember some chatter from Digium that they would not pursue Broadsoft functionality due to licensing or patent issues. I don’t know if that still holds true or not.

We are sadly in need of shared call/extension appearances and I hope this project can move forward to incorporate this functionality into Asterisk as a fully supported function.

Broadsoft SLA is an open standard, published and in front of the IETF.

That is why it is supported by SNOM, Polycom, Aastra, Yealink etc.

I don’t think it is Digium. It’s one guy Russel Bryant and he simply turns off when you talk SLA.

I am going to try an corner him at Astricon. It was very difficult to do last year but I did not make a huge effort.

Hi SkykingOH. Respectfully, is it a stable solution to use the Broadsoft patch for SLA? With Polycom phones? I have not looked at the patch. Of course the Asternic FOP2 does everything a person wants. Only in a web GUI though. And what about the SLA solution at the wiki link I reposted? Is that what you are talking about? Thanks.

Franklin -

Stable solution? Who knows yet. As I indicated YMMV, Your Mileage May Vary. To make it stable we need to test it on as many platforms as possible and get it up-ported to 1.8.

I have indicated the Asterisk SLA Station does not work the way you anticipate that is why it is not widely deployed nor is supported via FreePBX. I suggest you read up on how it works so you can prvide meaningful input.

can i ask you a question about your setup ?

carlosarze, who are you asking? Don’t ask to ask a question, if it is on the topic of SLA, just ask.