Vega Gateways - Call-Pickup

Vega Gateways - Call-Pickup

Table of Contents

Introduction

Call pick-up is a feature used in a telephone system that allows one to answer someone else's telephone call. The feature is accessed by pressing a pre-programmed button (usually labelled "Pick-Up"), or by pressing a special sequence of buttons on the telephone set.

Call Pickup in IMS/VOIP can be implemented as described in RFC5359.

Vega Implementation

In order to implement Call pickup in VEGA, we have implemented logic to handle the SUBSCRIBE message and then send NOTIFY for the respective/requested/subscribed leg to PBX.

Rest of the call pickup functionality will be taken care by PBX i.e. releasing current call and initiating call to new leg (pickupee).

Call Flow

Please note that below call scenario is tested/validated against SIPxecs PBX.

All the three legs i.e. A , B and C are connected to VEGA.

A is calling to B and while B alerting C is trying to pick B's call.

VEGA Configuration

Please execute below command in VEGA CLI in VEGA in order to enable this feature.

set _advanced.sip.subscribe.enable=1

References

  1. Session Initiation Protocol Service Examples - RFC5359

  2. Session Initiation Protocol (SIP)-Specific Event Notification - RFC3265