Today I was trying to contact two of my friends on blackberry. The messages were not delivered and I began to wonder if my BIS subscription has expired. Even though I had not received any notification I had reasons to suspect because just a few days before my Airtel step up plan had expired and I did not receive any notification. Just as I was about to check when I paid my last subscription fee I received a BB message from a friend. It was at that point that I realized that there was nothing wrong with my phone. Perhaps their own BIS subscriptions had expired or their phones were off or out of their network coverage area.