Very Computer

Hello,

Could you pleaseexplain me what are the major differences, advantages
and / or disadvantages of implementing a client/server application in C
using either sockets or TLI on the Solaris environment and TCP/IP
protocol ?

Please tell me what are the points to consider when choosing one or the
other way ?

Thanks,

Mario Desiderio

Don't give it a second's thought. Go with sockets.

____________________________________________________________________________
Doug Hughes                                     Engineering Network Services
System/Net Admin                                Auburn University

Quote:> Don't give it a second's thought. Go with sockets.

My opinion of the tli is its a much better model to work with, and gives you
lots of extra features. And you should also note that a lot of databases (ie
sybase and informix at least) implement tli drivers for solaris (perhaps this
is the speed issue again?)

Thanks,

    Giles

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Joerg

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    Giles

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Giles Douglas - Senior Software Engineer - Sailfish Systems Ltd - 212 607 3016

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Is it a major difference under solaris? I guess the reason the network layer in the
product I'm working at the moment is tli is because the person who wrote it grew up
with Sys V too, but I really don't see any advantage into turning into sockets. The
only advantage I can see with it is I could call writev to write a vector instead
of calling t_snd with flags set to T_MORE.

TLI does, of course, have the ability to close a socket for writing, but still read
from it, which one can't do in sockets (can you? - well other than the linger
option on the socket that is)

    Giles
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Giles Douglas - Senior Software Engineer - Sailfish Systems Ltd - 212 607 3016

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Quote:>TLI does, of course, have the ability to close a socket for writing, but
>still read
>from it, which one can't do in sockets (can you? - well other than the linger
>option on the socket that is)

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Quote:

>I've worked with a number of client server applications for Sys V unixes,
>including solaris, and was always told that the tli got a little extra speed
>out of the process for high volume networking, since its lower to the actual
>implementation (on sun anyway, because sockets are implemented on top of tli)

In current Solaris releases, sockets are now back as system
calls (and I presume this improves performance even further,
but I've not actually measured again since this happened).

In the application I work on, we can build either TLI or
socket based comms. I don't think any of the 20 or so unixs
we support are actually built with the TLI varient any more.
For various reasons (performance and bugs mainly), they've
all reverted to sockets now.

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Andrew Gabriel
Consultant Software Engineer

Quote:> I've worked with a number of client server applications for Sys V unixes,
> including solaris, and was always told that the tli got a little extra speed
> out of the process for high volume networking, since its lower to the actual
> implementation (on sun anyway, because sockets are implemented on top of tli)

I say "vanilla" because with Solaris 2.6 Sun actually put all the socket
calls into the kernel.

Quote:> My opinion of the tli is its a much better model to work with, and gives you
> lots of extra features.

        Rich Stevens

Quote:

>> My opinion of the tli is its a much better model to work with, and gives you
>> lots of extra features.

>"Features"?  I think you mean "unnecessary complexity" :-)  And in terms of
>a "better model" just compare sockets and TLI with regard to (1) accepting
>new connections, (2) getting and setting options, (3) handling the closing
>of a connection.  Sorry, but if I can do something with, say 30 lines of
>code using sockets, but it takes, say 100 lines of code with TLI, that does
>not equate to a better model.

        TLI allows you to receive "call user data" without accepting
        a connection. You need this to handle ISDN calls in some cases.

Joerg

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URL:  http://www.fokus.gmd.de/usr/schilling    ftp://ftp.fokus.gmd.de/pub/unix

: > Some time ago, a guy from Sun pointed out that th esocket
: > implementation on Solaris is faster than tli.

My understanding is that perhaps the best way to describe the relative
speeds of sockets and TLI on Solaris is "fluid" or "changes depending
on release."

: Does anyone have any evidence of this (in terms of speed)? I can't
: find a reference on dejanews. All I discovered is that I was in fact
: wrong that sockets are on top of tli (oops) - both sockets and tli
: are on top of streams. Apologies for my slight misconception.

Netperf has tests available using both sockets and XTI interfaces, so
if someone wanted, they could measure a TCP_STREAM test and an
XTI_TCP_STREAM test and also compare a TCP_RR test to an XTI_TCP_RR
test.

rick jones
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Quote:> I prefer the socket programming model too, but there is a feature you cannot
> have with sockets:

>    TLI allows you to receive "call user data" without accepting
>    a connection. You need this to handle ISDN calls in some cases.

        Rich Stevens

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____________________________________________________________________________
Doug Hughes                                     Engineering Network Services
System/Net Admin                                Auburn University

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In 2.5.1 and before, sockets are implemented in sockmod and TLI in timod.
You have one or the other.

But I believe the socket side of things was actually better optimized,
using synchronous STREAMs.

In 2.6, this changed even more with sockets being system calls directly
(though on top of STREAMs).  This makes the system calls faster but
doesn't necessary adds read/write perf.

Casper
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Statements on Sun products included here are not gospel and may
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