What’s
signaling?
-Signaling is the control signal
transferred between communication devices( include user termination, switch
devices, etc).
-In the communication network, except the
signal used to transfer services information, there is information transferred
in the network , and such information is not for voice, images or characters
about services, but the control signal between communication devices, such as
occupancy, release, the busy or free state of devices, the called number, etc.
that all are control signals
Signaling
classification-by signaling transfer mode
-CAS (Channel Associated Signaling ):
-Channel Associated Signaling is in-band
signaling in which user call data and signaling are combined.
--CCS (Common Channel Signaling ):
---Common Channel Signaling is a signaling
system used in telephone networks that separates signaling information from
user data. Usually TS16 (Timeslot 16) on a E1 interface and TS1 (Timeslot 1) on
a T1 interface, are exclusively designated to carry signaling relating to other
traffic channels.
Channel
Associated Signaling
Common
Channel Signaling
Signaling
network
-No.7 signaling network is a specific
network which is used to transfer the No.7 signaling
--It is composed of SP, STP and
signaling link
-Signaling network is a independent
network form telephone network, in china the No7 signaling network has 3 layers
--HSTP
--LSTP
--SP
Between
two SP (SP or STP) there is a signaling link
The
dual plane structure of signaling network
SP
and STP
-SP:
SP is a node of signaling network to send or receive the signaling message, and
is a initiation
or destination of the signaling message
-OPC:
it is a signaling point to generate the signaling message
-DPC:
it is a signaling destination
-STP:
if some signaling point is neither OPC nor DPC, it’s function is only to
transfer the signaling message from one signaling link to another signaling
link, this SP is STP
Signaling
point
-24-bit signaling point combination
-14-bit signaling point combination
Signaling
link and signaling link set
-Signaling
link:
--signaling
link is between 2 signaling points, and there are at most 16 signaling links
between 2 signaling points which are connected to each other directly; If there
more than 16 signaling links between 2 directly connected signaling points, the
local or the peer end should add new signaling point
-Signaling
link set:
--Signaling
link set is a group of signaling links which have same property, and these
signaling links are between 2 adjacent
signaling points
(SLC) Signaling link code and link number
-SLC
is the number of signaling link, SLC is unique between 2 adjacent signaling point, SLC has 4 bits, so SLC is
from 0-15
-Link
number is a number to distinguish the link in local office, it is unique in
local office
Direct
connection and similar direct connection
SLS
and SLSM
-SLS: SLS has 4 bits (00～0F),
is used to select signaling link for No.7
--SLS
is circularly
changed, in order to grantee the symmetrical burden of each link or
link set
-SLSM：signaling
link (link set) selection mask, it is indicated by a 4 bit code
Signaling
link (set) selection setting principle
-Setting principle , suppose there
are 4 link or link set:
Signaling
route
-Signaling route is a logical
conception which is used to indicate a path the signaling message go through
from OPC to DPC
