3 ms·
When you're mainly working with 32bit CPUs (or less) and the year of overflow is almost 50 years in the future I can forgive them for considering it was good en
by simias 10y ago
When you're mainly working with 32bit CPUs (or less) and the year of overflow is almost 50 years in the future I can forgive them for considering it was good enough at the time. Maybe they thought that by the time it was going to be an issue somebody else would've replaced it?
It's in the same bag as IPv4 "only" supporting a few billion addresses, hindsight is always 20/20...
Moreover even 64bit timestamps wouldn't be good enough for certain applications that require sub-second precision. PTP (the precision time protocol) for instance uses 96bit timestamps to get nanosecond granularity. You always have to compromise one way or an other.
- dboreham 10y agoIPv4 as designed didn't support anything like a few billion addresses. We had to invent CIDR to get there, years later.
- simias 10y agoAre you sure about that? If we're talking as IPv4 as specified in RFC 791[0] (dated September 1981) it seems to support billions of addresses already: > Addresses are fixed length of four octets (32 bits). An address begins with a network number, followed by local address (called the "rest" field). There are three formats or classes of internet addresses: in class a, the high order bit is zero, the next 7 bits are the network, and the last 24 bits are the local address; [...] 7 bit network times 24bit local addresses is already more than two billions. [0] https://tools.ietf.org/html/rfc791 https://tools.ietf.org/html/rfc791
- jcranmer 10y agoIt supported billions of addresses, but only millions of networks. The registry could only give out 128 16-million address chunks, 16,384 64k chunks, and ~2M 256 address chunks. IPv4 was running out of class B's, those 64k address chunks, when CIDR was introduced.
- dboreham 10y agoI'm sure because I was there, at the meetings when CIDR was proposed and adopted.