OTTAWA -- Building on its rural market network evolution initiative announced in August 2002, Nortel Networks (NYSE:NT)(TSX:NT) today announced software enhancements designed to position independent operating companies (IOCs) to reduce operational expenses, boost security and deliver new, revenue-generating services to rural subscribers.Nortel Networks has also announced expansion of its service and support program for Nortel Networks DMS-10 carrier-class switching system customers, and the return of its popular SR-10 program to help IOCs more efficiently and cost-effectively plan long-term network evolution."These steps are the latest in an ongoing initiative intended to help our large base of rural market customers evolve their networks to a more cost-effective packet infrastructure at their own pace, preserving existing investments while laying the foundation for new, multimedia services in the future," said Sue Spradley, president, Wireline Networks, Nortel Networks."Nortel Networks commitment to investment in our DMS-10 product, coupled with our leadership position in voice over packet, will help service providers, including IOCs, deliver the same quality services to subscribers in rural markets as those in major urban centers," Spradley said.Scheduled to be available for 'pre-order' in July 2003 and delivery in October 2003, Nortel Networks DMS-10 504 software release will position service providers to offer Simultaneous Ringing, Telemarketer Call Screening, and other new, revenue-generating services on DMS-10 based networks. The carrier-class DMS-10 switching system, which has been listed with the Rural Utilities Service with each new software release, will also position service providers to migrate to fully-packetized networks at their own pace.Nortel Networks Corp.