IBM 3708 Description page 123

SNA Host
Data Stream:
Line: SDLC Secondary, Half Duplex Data Transmission
Point-to-point or multi-point
From SNA Host
~
t
To SNA Host
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
. Received Transmitted
Data Data
SDLC Link Level Headers/Trailers
removed
SNA Level Headers removed
:-------------------r---------------------~
ASCII
Screen
Image
Translation
EBCDIC to ASCII
(Host Data)
•
DEVICE
BUFFER
Device Control Traffic
SDLC Link Level Headers/Trailers
added
SNA Level Headers added
:------------------------1----------------~
Translation
ASCII to EBCDIC
(Terminal Data)
t
(such as Highlighting, cursor control)
•
WRITE
RECEIVE
•
QUEUE
QUEUE 1
I I
XMIT
ECHOPLEX
RCV
DATA
t
Transmi tted
Received
I
Data
Data
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
To ASCII Device
~
t
From ASCII Device
Terminal
Data Stream: (ASCII device data stream)
Line: SIS ASCII, Full Data Duplex
Point-to-point only
Figure 4-1. 3708 Protocol Conversion - Internal Data Flow
4-2
IBM 3708
Description