Nokia 7705 SAR - Page 182

7705 SAR Interfaces
182
Interface Configuration Guide
3HE 11011 AAAC TQZZA Edition: 01
Figure 27 Raw Socket Packet Processing
3.6.6.2.1 Raw Socket Processing for UDP Sessions
When the local host receives a UDP packet from a remote host, it queues the packet
and sends it over the serial link. The local host remembers the UDP session while
there is still data to send from the serial link. If further packets are received for the
same session, they are queued behind the already queued packet. After all the
queued data has been sent over the serial link, the session is removed from the
system. An associated UDP remote host for the serial link must be configured to
have serial data sent back to the remote host from the serial port.
When a packet is received from the serial link based on end-of-packet (EOP)
requirements, the data is copied and sent in a UDP packet to each configured remote
host.
3.6.6.2.2 Raw Socket Processing for TCP Sessions
An open TCP session from a remote host to a raw socket’s local host is kept open
until either the remote host terminates the session or the TCP inactivity timer expires.
When a TCP session is open, all packets received from the remote host are queued
for the raw socket serial link and sent over the serial link until no packets remain in
the queue.
26210
RTU(1)
7705 SAR-18/8/H/Hc
Serial
port
Substation
Central location NOC
Configurable inter-session
time between each
queued data stream from
each socket session
Packets are queued for
each group of socket sessions
until the serial line becomes
free to transmit
Round robin all
session queues
(flush each
queue before
proceeding
to next)
Src: Z, Dest: X, sPort: Bp, dPort: 5000
Src: Z, Dest: X, sPort: Ap, dPort: 5000
Src: C, Dest: X, sPort: Cp, dPort: 5000
Server (local host) sessions
Layer 3
IP/MPLS
services
Eth
port