Re: OpenTransport...
Re: OpenTransport...
- Subject: Re: OpenTransport...
- From: Peter Sichel <email@hidden>
- Date: Fri, 25 Oct 2013 19:40:00 -0400
I have fond memories of Open Transport (Mentat/TCP/Portable Streams) as well. Once I figured out how to configure multi-link multi-homing, it made a kick-as router (IPNetRouter).
STREAMS was originally developed by Dennis Ritchie as a message based plug-in architecture for networking. The design was way ahead of the BSD stack and more efficient, but the open source implementations sucked. Mentat's implementation was awesome, but the NeXT team that had taken over Apple needed an open source solution and they couldn’t be persuaded to buy Mentat and replace the networking stack they already knew.
In my humble opinion, keeping Mentat Portable Streams would have been less work and set the gold standard, but Apple’s leadership couldn’t see it so they ended up re-working the BSD stack repeatedly to create more clumsy solutions to problems STREAMs had already solved.
NKEs in Mac OS X are a horrible kludge. There’s no introspection to determine the network stack order. Inserting NKEs didn’t even maintain the network stack order at first. Every packet needs to be tagged (adding another mbuf) so you can tell if you have already seen it when you re-inject it. They are inefficient, clumsy, and unreliable if you need more than one at a single level. Mac OS X does not support robust networking extensions and missed the opportunity to be a networking powerhouse. As a result, a number of products and developers went out of business.
To Apple’s credit, BSD was “good enough” and they made it work.
Enjoy!
- Peter
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Macnetworkprog mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden