Step 1: Why IP •   Telephony?     Step 2: Business •   Justification     Step 3: Consider •   Your Options     Step 4: Free •   Planning Guides     Step 5: Request a •   FREE Quote     IP Telephony Case Studies Erlanger Health System This case study discusses how health-care leader Erlanger Health System uses a converged voice and data network from Nortel Networks as a platform for advancing patient care. PPL Corporation (PDF, 321KB) This case study discusses how PPL teamed with Nortel Networks to transition its network to IP Telephony and empowered a flexible workforce to deliver optimal customer service, while protecting its infrastructure investment.