| 摘要 |
<p>An apparatus (Fig. 4, 412) is described that has a line level selection unit (401) and a path level selection unit (402). The line level selection unit (401) forms a primary traffic stream (425) and a second traffic stream (426). The primary traffic stream (425) comprises a plurality of signals that are received on one or more working or protection ingress lines (405). The secondary traffic stream comprises the path level protection signal for each of those signals within the primary traffic stream (425) that have path level protection. The path level selection unit (402) receives primary and secondary traffic stream (425, 426) and form an ingress traffic stream (410) by replacing with its corresponding path level protection signal any of those signals within the primary stream that have path level protection and have failed.</p> |
