RE: Sockets client in RPGIV

[Jim Langston <jlangston@xxxxxxxxxxx>]

Have you ever downloaded a program/file from the internet, went to run it
and it was bad so you had to download it again?  I have.  Not often, maybe 2
or 3 times over the years.

TCP/IP is guaranteed delivery.  TCP/IP encapsulates the data in a TCP/IP
capsule and sends it.  I don't recall a CRC value in the TCP/IP header
(although I could be mistaken, I don't think I am).

It is very seldom that you will get bad data, but one random electron flip
from a 1 to a 0 (or vice-versa) can render a 10 megabyte transfer worthless.

I would go with the CRC check.

This is just my opinion and stated from observance, not from fact.

Regards,

Jim Langston

Why let facts obscure the truth?

-----Original Message-----
From: DeLong, Eric [mailto:EDeLong@Sallybeauty.com]

Group,

I got a q+d project this morning to write a socket client app.  The
programmer at the other end wants to include a check digit to validate the
record before processing.  I always thought TCP handled all data validation,
eliminating the need to add this layer of validation.  He claims that bad
data and/or garbled records will still sometimes be returned to the
application, making this additional testing and process control necessary.
I have doubts.  Can anyone confirm that this is necessary, or even useful?
TIA.

Eric DeLong
Sally Beauty Company
MIS-Sr. Programmer/Analyst
940-898-7863 or ext. 1863