BLF Example Scenario

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Revision as of 22:58, 26 May 2017

Overview

This is a brief attempt to capture information which was necessary to achieve success in configuring "BLF" (Busy-Lamp-Field) feature on VoipPhones (Grandstream GXP2160 in this case) new deployment at a small office. For purposes of this summary / so it makes 'sense' I am providing 'context info' which is strictly speaking not necessary; but hopefully it will help provide clarity around the use-case scenario for this feature / and how to make it work (possibly).

Scenario

New deployment of Voip phones in a small office. For purposes of discussion here, they have 4 Handsets, each with its own DID; and sub account configured for each VOIP Grandstream phone device. Inbound calls for the office are aimed at the 'reception' phone number; which points to a ring group; for which all 4 phones are members. Thus anyone in outside world calling in to the 'office number' will generate a ring on all 4 phones concurrently / and anyone in the group can pick up.

In some cases, one person picks up, talks briefly, and then wants to transfer the call to one of the other lines. It is useful to know prior to starting this process, if the person in question is already on their line / are busy and not available to take the call. The BLF feature allows you to see the "On-hook / Off hook / ringing" status of other lines in your office which you are monitoring.

The BLF "Busy Lamp Field" is (apparently?) a common feature on "old world" phone systems (aka this client had old Nortel phones that were being replaced; and they had BLF configured). Apparently people who talk on the phone lots - find it helpful. My client asked me to get it working, and it was indeed possible, and actually not too terrible at all once the proper steps were clear.

Concise Steps to Get it working

1. Confirm if your phone handset device appears to support BLF feature. (note in my case I was working with GrandStream GXP 2160 handsets, and they do support this feature; as do apparently many other related grandstream 'business class' handset voip phones). I have the impression that many similar handsets from other vendors implement this feature. I have not tested any other handset for this feature.
2. Decide what specific single VoipMS server these client devices must all be connected to. In the case of this example I will make that choice to be, "montreal3.voip.ms"
3. Make a request to Voip.MS technical support via a ticket, where you specifically tell them, "I want to enable BLF feature for my account and all linked subaccounts, which are registered to the specific Voip.MS voip server, montreal3.voip.ms". They will enable features server-side which will allow these sub-accounts to monitor BFS status of other sub-accounts who are registered on the same / correct / designated voipMS server.
4. Wait patiently for them to confirm back that they have done this. Until it is done, you must wait.
5. Once it is done, login to the web-admin UI for each of the 4 handsets. Adjust the BLF setting as shown below, on each phone.
6. Now, on each phone LCD display console you will have 3 BLF status indicators which list the NAME designated for each BLF monitoring; and the HOOK_STATUS will be apparent via colour coding. You are done. Test it, happy days.

More Detailed Steps to get it working

• Background - BLF is effectively granting 'trusted devices' the permission to 'snoop' and 'notify' on call hook status with other trusted devices / that are all registered on the same specific VoipMS server. So you only configure a single SIP account on each hadnset. You do not provide credentials for multiple accounts on each handset. Rather, each handset authenticates (as per normal) to the SIP server with just one SIP account / and in addition to its normal call functions, you configure BLF so that you specifically designate "hey, this programmable button number one, corresponds to JOE_VOIP_PHONE_ACCOUNT with SIP_ACCOUNT_ID, and I want you to monitor and display his on-off-hook/call status to me please. And then programmable button nubmer two, corresponds to JANE_VOIP_PHONE_ACCOUNT with SIP_ACCOUND_ID_FOR_JANE, and I want same monitor display for her phone, adjescent to programmable button number two on my phone. Etc etc."
• From what I can tell the grandstream phones I was working with support inherently 6 x programmable buttons out of the box with no-questions-asked for BLF monitoring if desired. It seems that it might? be possible to add more lines / buttons; but I am not sure; haven't tested; and don't have easy physical access ot the phones still so I am not inclined to test beyond the use case I already have any know. If you want BLF for more than 6 neighbour devices, you will need to play with it yourself and then update the wiki to tell the world what you have learned :-)

• So, here is a concrete example to nail it all home.
• For the client's office in question, We have SIP sub-accounts defined, as follows
• SIP Username / SIP PASS / EXTENSION / COMMENT

1. 123456_user1 / 1SecretPass / 101 / JOE SMITH is user of this phone
2. 123456_user2 / 2SecretPass / 102 / JANE SMITH is user of this phone
3. 123456_user3 / 3SecretPass / 103 / JIM JONES is user of this phone
4. 123456_user4 / 4SecretPass / 104 / JOHN JAMES is user of this phone.