Some networks lack sufficient WAN trunk bandwidth to transport higher bit rate video (uncompressed or compressed) or data services. Although upgrading trunk bandwidth rates may be an option for some customers, high monthly circuit costs and limited service availability often make this choice unattractive or impractical. For customers in this position, the MD8000-SPU-Bulk line module overcomes these limitations by logically combining multiple lower speed trunks into a single high speed pipe, giving users the ability to transport high bit rate video and data connections over lower speed and lower cost network trunks.
SPU-Bulk line cards work in pairs, with each SPU-Bulk card located in a different chassis. The transmitting SPU-Bulk card sends filtered input stream packets to multiple trunks (paths) following a selected distribution algorithm. The receiver restructures packets received from multiple paths and outputs them in a stream or streams (however, no packet reordering is made but packets will be output following the order of arrival). The transmitter and receiver can Bulk transport up to 16 filtered streams over up to 4 separate paths (lines).
This board supports two distribution algorithms: Round Robin and Priority Order. The Round robin algorithm spreads the load evenly over all paths, ensuring the efficient transport of high speed video or large volume file data. The Priority Order algorithm uses paths in order of their priority, with high priority paths taking precedence over low priority paths. This helps to minimize the arrival time difference and packet disordering among multiple paths, making it a good fit for high-bit-rate stream transportation.
The SPU-Bulk module supports three IP network transportation modes: Tunneling Mode (RTP encapsulation), Header Translation Q-in-Q mode (VLAN tagging), and Header Translation (Overwrite mode).