Calisto: A Low-Power Single-Chip Multiprocessor Communications Platform

0272-1732/03/$17.00  2003 IEEE Published by the IEEE computer Society Telecom service providers are augmenting telephony networks with packetswitched networks, enabling converged voice, data, and multimedia transport over a single network infrastructure. However, the profound mismatch between circuit-switched telephony networks and packet-switched data networks makes providing converged voice and data services difficult. Voice over packet (VoP) services such as voice over Internet protocol (VoIP) must deliver the same high reliability and quality of service as the public telephone network while compensating for packet overhead, delay, jitter, and loss. VoP services require extensive signal processing for echo cancellation, voice coding, and modems. They also require packet relay services for signaling, tones, fax, and modem data. VoP and media gateways adapt voice, data, and multimedia traffic to work for different network types and provide packet-based services. Because services vary dynamically with each voice channel, gateways must support many different services concurrently and in real time. Gateway capacities range from tens to tens of thousands of voice channels. Calisto integrates the components of a multichannel gateway into a single-chip lowpower communications platform that uses multiprocessor parallelism supported by extensive on-chip memory systems. Its power efficiency and programmability enable high channel density and flexibility, achieving 30 times the density of prior designs within existing power and volume envelopes. Telecom providers are deploying two generations of Calisto architecture, the Broadcom BCM1500 and BCM1510, in enterprise and carrier-class communications systems.