Cloud Storage Options
Generally, public cloud storage option has less upfront cost, high accessibility, high resilience to hardware failures, and geographic redundancy. Also, with public cloud we have less control over the saved objects, which in turn might lead to privacy and security concerns. Performance wise, public clouds have higher latency for storage and retrieval, compared to private cloud storage. Table 2 shows the comparison of public and private cloud storage options. We have considered Google storage and Amazon S3 as public cloud storage providers. Google storage provides two options, standard and DRA (durable reduced availability). Compared to standard, DRA is low cost option with tradeo of reduced availability. InstaGENI rack is used as private cloud storage provider.
Table 2 Public cloud vs Private cl
Firewall/NAT Traversal
Many middle boxes on the Internet, such as, NAT, Firewalls, and ALG (application level gateways), will block the incoming TCP connections into local network. Moreover, some middle boxes will block the whole UDP traffic, practically making it impossible to achieve UDP based direct streaming. Even if we are able to achieve this streaming in some cases through a mechanism called hole punching, the continuous streaming of recorded content consumes con- stant bandwidth, creating steady cross-traffic for other network applications in LAN. For example, a 1280X780 resolution video consumes roughly 3 Mb/s band- width. So, it will constantly consume 30% on a 10 Mb/s upload connection.
