When the Cisco 1-Port Channelized STM-1/OC-3 SPA Version 2 is configured in SDH framing mode, it supports channelization into 63 independent E1 channels (VC-12 mapping). When configured for SONET framing mode, the SPA supports channelization into 84 independent T1 channels (VT1.5 mapping or CT-3 mapping into STS-1).
Multilink Point-to-Point Protocol (MLPPP) is supported in hardware to enable link aggregation greater than T1. Up to 12 individual T1s can be combined within a multilink bundle that appears to be a single IP link. This feature allows service providers to provision greater-than-T1 bandwidth on an incremental basis, without requiring migration of the circuit and customer-premises-equipment (CPE) infrastructure to T3 facilities. A maximum of 42 multilink bundles can be configured on each SPA, with at least two T1 links in each bundle.
The Cisco 1-Port Channelized STM-1/OC-3 SPA Version 2 is hot-swappable and supports service-transparent online insertion and removal (OIR), allowing removal of the SPA without affecting the carrier card and other SPAs.