Limitations
Segmented downloading technology cannot magically solve all downloading problems. There are mathematical constraints on the effectiveness of the technology.
In a group of users that has insufficient upload-bandwidth, with demand higher than supply. Segmented downloading can however very nicely handle traffic peaks, and it can also, to some degree, let uploaders upload "more often" to better utilize their connection.
Data integrity issues
- Very simple implementations of segmented downloading technology can often result in varying levels of file corruption, as there often is no way of knowing if all sources are actually uploading segments of the same file.
- Data corruption problems have led to most programs using segmented downloading using some sort of checksum or hash algorithm to ensure file integrity (to receive file intact) and uniqueness (to not receive bits of other similar files).
- Usually MD5 and SHA-1 hashes are preferred in most segmented download protocols, but CRC-64-ECMA would suffice in most cases. In cases where only MPEG files are being sent CRC-32-MPEG would also be acceptable.
- In the future most segmented downloading technologies will probably use layered hashes and checksums like WHIRLPOOL, SHA-256, SHA-512 and CRC-64-ECMA (for individual segments) to unquestionably guarantee data integrity. MD5 and SHA-1 have been determined to be cryptographically weak with respect to protecting data integrity.
Read more about this topic: Segmented Downloading
Famous quotes containing the word limitations:
“The motion picture made in Hollywood, if it is to create art at all, must do so within such strangling limitations of subject and treatment that it is a blind wonder it ever achieves any distinction beyond the purely mechanical slickness of a glass and chromium bathroom.”
—Raymond Chandler (1888–1959)
“No man could bring himself to reveal his true character, and, above all, his true limitations as a citizen and a Christian, his true meannesses, his true imbecilities, to his friends, or even to his wife. Honest autobiography is therefore a contradiction in terms: the moment a man considers himself, even in petto, he tries to gild and fresco himself.”
—H.L. (Henry Lewis)
“Much of what contrives to create critical moments in parenting stems from a fundamental misunderstanding as to what the child is capable of at any given age. If a parent misjudges a child’s limitations as well as his own abilities, the potential exists for unreasonable expectations, frustration, disappointment and an unrealistic belief that what the child really needs is to be punished.”
—Lawrence Balter (20th century)