SAFN:

SDH Add-Drop and Access Multiplexer

 SAFN

SAFN
SDH Add-Drop and Access
Multiplexer

Overview
 SAFN
OVERVIEW (1)

SAFN is a Transport/Access equipment for transmission of voice and data signals

on digital networks. It’s particularly suitable for applications in railways, motorways,
pipelines, etc. (“utilities” applications).
The equipment can realize multiplexing, submultiplexing, cross-connecting and
routing functions.

SAFN can manage different types of user

interfaces multiplexing these voice and data
tributary channels in one or more higher rate
streams.

These multiplexed streams are managed by

means of interfaces suitable both for the
connection to others Transport equipments
(Exchange Terminals) and for the transmission
directly on copper or fibreoptics (Line Terminal).
 SAFN
OVERVIEW (2)
The SAFN applications are mainly directed to private networks, which require
performances more complex and diversified than the public ones: integration of
Transport and Acces functions, specific interfaces, Point-Multipoint and Omnibus
connections, remote management of not-controlled stations, high survival to the
equipment and network failures to ensure the continuity of the high priority
services.

In the equipment are integrated also a VoIP

gateway function and an IP-PBX to realize a
Service Telephone System.

So, in applications with a low number of users

(typically the intermediate stations along
pipelines or railways), SELTA solution offers the
advantage to require a single equipment instead
of a multiplicity of typologies (SDH Add-Drop,
Primary Multiplexer, Submultiplexer, Router and
PBX).
 SAFN
SAFN – Multifunctional network node

Low rate data S

users. 64 Kb/s G.703.
M
V28 U
X
Modem Nx64 Kb/s, 2 Mb/s xDSL.
xDSL

Nx64 Kb/s data users.

V35 / V11 / G703. M
U ADM STM-N
Voice users X
FXO / FXS / 2/4 wires. E1

VoIP
IP users Gateway Nx64 Kb/s, 2 Mb/s G.703.
Router IP/
Ethernet 10/100BT.
Bridge

IP-PBX
 SAFN
PERFORMANCES (1)

TM-1 and ADM-1 (Terminal Multiplexer and Add-Drop Multiplexer in STM-1 SDH Networks)

Multiplexing, Submultiplexing, Drop/Insert and Cross-Connecting in Transport/Access functions

IP Routing function, with co-existence of TDM and IP traffic on the same carrier

VoIP Gateway function

IP-PBX for a Service Telephone System

Link protection (1+1, MSP)

Channel protection (redundancy path, SNCP)

Priority list for the synchronization sources and automatic mechanism for ring networks

Point-to-Point, Point-Multipoint and Omnibus connections
 SAFN
PERFORMANCES (2)

Redundancy of the common parts

Non-blocking switching matrix

Channels allocation independent from the physical position in the subrack

EOC for the remote diagnosis, configuration and software updating (also by remote)

Configuration modification without traffic interruption

Management of digital inputs from external devices and digital outputs to external devices

Integrated dial-up manager

Management of the connections quality and of alarm historical log in non-volatile memory
 SAFN
PERFORMANCES (3)

Line Terminals: 155 Mb/s (STM-1) optical and electrical

Shdsl (ETSI TS 101 524, ITU-T G.991.2)

Data interfaces: 2 Mb/s and Nx64 Kb/s G.703
Nx64 Kb/s V.11, V.35, V.36
64 Kb/s G.703 Co-directional
1.2 Kb/s … 19.2 Kb/s X.20/X.21 V.24/V.28

Voice interfaces: 2/4 wires + E&M
FXO
FXS

Network interfaces: Ethernet 10/100BaseTx
 SAFN
RELIABILITY

To increase the equipment reliability, the following parts can be duplicated in the
SAFN-S mechanics:

Power supply

CPU

Configuration (non volatile memory)

Equipment clock

This redundancy, obtained duplicating the UA and UC units of the basic part
constitutes, for all purposes, a ‘hot stand-by’.
Then, the SAFNs can continue to work on the stand-by unit.
A proper signalling is returned to the management system to individuate the operating
condition of the stand-by part.
 SAFN

SAFN
SDH Add-Drop and Access
Multiplexer

Functions
 SAFN
FUNCTIONS

Multiplexer SDH / PDH

Cross-Connect SDH /PDH

Remote Bridge / IP Routing

Service Telephone System
 SAFN
FUNCTIONS

Multiplexer SDH / PDH

Cross-Connect SDHMultiplexer
TM-1: SDH /PDH over optical 155 Mb/s

Remote Bridge
Primary/ IP Routing over 2 Mb/s stream (E1 Framed)
multiplexer

Service Telephone System
Submultiplexer over 64 Kb/s stream (frame X.50)
 SAFN
FUNCTIONS

Multiplexer SDH / PDH

Cross-Connect SDH /PDH
ADM-1:/ SDH

Remote Bridge VC12 Cross-Connect over STM-1 frame
IP Routing

Service Telephone System over E1 Framed streams
TS Cross-Connect

Subrate Cross-Connect over 64 Kb/s streams (E1 TS)

 SAFN
FUNCTIONS

Multiplexer SDH / PDH

Cross-Connect SDH /PDH

Remote Bridge / IP Routing
Co-existance

Service Telephone of TDM ed IP users on the same carrier
System

Programmable bandwidth for circuit/packet

 SAFN
FUNCTIONS

Multiplexer SDH / PDH

Cross-Connect SDH /PDH

Remote Bridge / IP Routing

Service Telephone System
VoIP gateway function (with SIP signalling protocol)

IP-PBX function
 SAFN
FUNCTIONS

Multiplexer / The multiplexing is made without constraints about the allocation,

deriving neither from the interface typology nor from the physical
Submultiplexer position of the unit in the subrack.
The stream deriving from the submultiplexing can be directly used in
multiplexing and cross- connecting operations, without requiring the
equipping of aggregate interface units.

Drop / Insert About voice channels, also the associated signalling is cross-
connected in “TS16” time-slot, together with the respective voice.

The realisation of the cross-connections between voice and data

channels, coming from the different aggregates, doesn’t require the
Cross-connect presence of the channel unit correspondent to the cross-connected
channels.

With IP-routing and bridging functions it is possible to have both

packet-switching and circuit-switching on the same equipment (so on
the same carrier).
Router/Bridge This solution is really suitable using a variable baud rate carrier (as
g.shdsl).

(These functions can be combined inside a single network node)

 SAFN
FUNCTIONS: Multiplexer

PBX
SAFN
SDH link
xDSL link
Radio link
Data

PBX E1-G703
SAFN xDSL
STM-1

Data V28
= FXS-FXS connection
SAFN
V11
= FXO-FXS connection
Data
= 2/4 wires - 2/4 wires connection

= Low speed data Data

= High speed data

Multiplexing of 2 Mb/s, 64Kb/s and <64Kb/s (submultiplexing)

 SAFN
FUNCTIONS: Cross-connect

SAFN SAFN
STM-1

g.shdsl

SAFN
STM-1
g.shdsl

SAFN SAFN

= 2Mb/s channel = 64Kb/s channel = 9.6Kb/s channel = 4.8Kb/s channel

Cross-connection on 2 Mb/s, 64Kb/s and subrate (<64Kb/s) channels.

For cross-connection it is not necessary the channel board.
In voice channels also the associated signalling is automatically cross connected.
 SAFN
FUNCTIONS: Router / Bridge

TDM
SAFN
Users

SDH link
xDSL link
IP Radio link
TDM 10/100BT

TDM
Users SAFN E1-G703
xDSL
STM-1

TDM
SAFN
Users
10/100BT

= SAFN Router/Bridge function 10/100BT

Programmable bandwidth for TDM channel and IP.

 SAFN
CONNECTIONS

A1 A2 Point to Point connection

A2
+

A1
+ Point to Multipoint connection

+
A3

PP1
PC
+ PP2 Ominibus connection

PP3

All the connections can be implemented both on voice and data channels and can be relative both to tributaries and
aggregates streams. Both transit channels (on cross-connections) and local channels can be indifferently involved
in the connections.
Proper solutions are taken in the equipment to ensure that the failure or the absence of a channel unit, related to a
Point-Multipoint or Omnibus connection, causes such a state on the aggregate stream not to damage the correct
connection among the other channels involved in the Point-Multipoint or Omnibus structure.
 SAFN
LINK PROTECTION 1+1 (Multilex Section Protection)

First Carrier

SAFN Second Carrier SAFN

SDH link
xDSL link It is possible to assign two different interfaces to each
Radio link aggregate streams. SAFN will provide to automatically
implement the branching in transmission and the
switching in reception.

The (1+1) automatic protection will start as soon as an

First Carrier alarm on reception side is detected, which indicates the
loss of service on the used interface.
User
If both interfaces are on the same board the equipment
Second Carrier manages the switch in 50 ms.

MSP Protection works both on SDH stream and on multiplexer/submultiplexer aggregate.

 SAFN
CHANNEL PROTECTION (Sub-Network Connection Protection)

Before the failure

SAFN

SAFN
SAFN

It is possible to assign two different streams to a

single interface. SAFN will provide to execute
SAFN the branching in transmission and the switching
in reception.
= active channels
The switching in reception consists in assigning,
= back-up channels automatically, the interface to the stream which
presents a “pilot criterion”, which signals the
connection integrity.

SNCP Protection works both on SDH VC-12 and on multiplexer/submultiplexer channel.

 SAFN
CHANNEL PROTECTION (Sub-Network Connection Protection)

After the failure

SAFN

SAFN
SAFN

It is possible to assign two different streams to a

single interface. SAFN will provide to execute
SAFN the branching in transmission and the switching
in reception.
= active channels
The switching in reception consists in assigning,
= back-up channels automatically, the interface to the stream which
presents a “pilot criterion”, which signals the
connection integrity.

SNCP Protection works both on SDH VC-12 and on multiplexer/submultiplexer channel.

 SAFN
DIGITAL IN/OUT FROM/TO EXTERNAL DEVICES

OUTj
SAFN
INj
SDH link
xDSL link
Radio link

E1-G703
SAFN xDSL
STM-1
OUTj
SAFN
INj

Network
Management
System

From Network Mamagement System it is possible to write all OUTj and

to read all Inj signals, using the Embedded Operational Channel (EOC).
It is possible to configure Inj signals as alarms.
 SAFN
SYNCHRONISM MANAGEMENT: Ring network

1 Before the failure

FREE RUNNING 0

SAFN SAFN
To correctly manage also the ring
and meshed network topologies
(without the generation of
1 1
‘timing-loop’), some information
on the synchronism state must be 0 1
transmitted among the SAFNs,
constituting the network nodes.

1/0
= synchronism status bit
SAFN
(1=OK, 0=KO)

0
SAFN

1
 SAFN
SYNCHRONISM MANAGEMENT: Ring network

1 After the failure

FREE RUNNING 0

SAFN SAFN
To correctly manage also the ring
and meshed network topologies
(without the generation of
‘timing-loop’), some information 1
0 1
on the synchronism state must be
transmitted among the SAFNs,
constituting the network nodes.

1/0 1
= synchronism status bit
SAFN
(1=OK, 0=KO)

1
SAFN

0
 SAFN
SYNCHRONISM MANAGEMENT: SDH and fiber/copper branch

Before the failure

SDH Network
SAFN SAFN
(ADM) (ADM)

ext
ext
1 1
1 1

1 1 1 SAFN
SAFN SAFN SAFN
(MUX) (MUX) (MUX) (MUX)
0 0 1

1/0 = Synchronism status bit

 SAFN
SYNCHRONISM MANAGEMENT: SDH and fiber/copper branch

After the failure

SDH Network
SAFN SAFN
(ADM) (ADM)

ext
ext
1 1
1 1

1 0 0 SAFN
SAFN SAFN SAFN
(MUX) (MUX) (MUX) (MUX)
1 1 1

1/0 = Synchronism status bit

 SAFN
REMOTE BRIDGE (remote LAN segments)

SAFN

SDH link
SAFN xDSL link LAN
SAFN
Radio link

LAN
LAN

This feature connects different LAN segment with SAFN carriers (or SAFN carriers
partition), so that remote users can hold themselves linked in the same LAN.
The equipment works as a “Layer 2 bridge” (based on MAC address).
The MAC addresses needed to update the MAC tables (formerly known as “forwarding
tables”) are transferred over the links between SAFNs.
= Bridge function With this architecture the efficiency is very high because rerouting on link failure is not
based on the spanning-tree algorithm, but on protection mechanism of SAFN solution
(fast and reliable).
 SAFN
IP ROUTER

SAFN
SDH link
xDSL link
Radio link

LAN

SAFN
SAFN
SAFN

LAN
LAN
This feature realize IP routing between Ethernet 10/100BT and SAFN carriers (or
SAFN carriers partition).
The equipment works as a “Layer 3 router” (based on IP address).
With this architecture the efficiency is very high because rerouting on link failure
= IP Router function
is not based on the dynamic routing algorithm typical of IP world (RIP, OSPF), but
on protection mechanism of SAFN solution (fast and reliable).
 SAFN

SAFN
SDH Add-Drop and Access
Multiplexer

Technical
Specifications
 SAFN
VERSIONS

• SAFN-S (450 x 480 x 240 mm, front I/O):

• Management of 14 card slots (both for aggregates and tributaries).
• Within the 14 card slots, up to 4 Line Terminal can be managed (also of different types -
fibreoptics or copper -).

• SAFN-M (250 x 480 x 240 mm e accessibilità posteriore):

• Management of 5 card slots (both for aggregates and tributaries).
• Within the 5 card slots, up to 2 Line Terminal can be managed (also of different types -
fibreoptics or copper -).
The SAFN-M version is particularly suitable for working “along the line” in the linear networks
with many access points characterized by low local traffic.

19” standard rack (also compatible with ETSI)

SAFN units can be replaced without changing I/O connections.

 SAFN
Multiplexing, Add-Drop and Cross Connect capability (Transport)

• Each equipment can manage up to 2 x 155 Mb/s streams (STM-1 Add-Drop

Multiplexer).

• Each equipment can manage a traffic capacity of 63 VC12 for each Add-Drop
direction (in the cross-connect function), of 8 VC12 (in the plesyochronous transport
function) and of 8 VC12 (in the synchronous access function).
 SAFN
Multiplexing, Add-Drop and Cross Connect capability (Access)

• Each equipment can manage a traffic capacity of 8 streams at 2 Mb/s as aggregates

(in cross-connect function) and of 12 streams at 2 Mb/s of aggregates and tributaries
(in the cross-connect and multiplexing functions).

• Each equipment can manage up to 32 X.50 structured time-slots at 64 Kb/s (among

aggregates and tributaries).

• Each equipment can manage up to 64 voice users in omnibus or Point to Multipoint

connections.

• Each equipment can manage up to 64 data users in Point to Multipoint connections

and up to 7 data users in each omnibus or Point to Multipoint (multi central)
connection.
 SAFN
ARCHITECTURE: Base units

• UA
This is the set of circuits which converts the main power supply in the internal voltages
necessary for the equipment operation.

• UC
It contains the circuits for the realisation of the following functionalities: Equipment
control by means of microprocessor, Generation of equipment synchronism,
Management of connections and cross-connections.

• US
It contains the circuits for the realisation of the following functionalities: Interface for
the external synchronisation source (SI interface), Alarm interfaces, Management
Interfaces.
 SAFN
ARCHITECTURE: Repetitive units (1)

Board Description

TM-1/ADM-1 One/Two fibreoptics 155 Mb/s interface and

eight 2 Mbit/s G.703 interfaces (TM1/ADM1)
2LSHDSL4w Two g.shdsl 2/4 wires interfaces (SHDSL).
Available also with remote power supply
2LSHDSL Two g.shdsl 2 wires interfaces (SHDSL)

4L2M-G703 Four 2 Mbit/s G.703 interfaces (L2M-G703)

2L2M-G703 Two 2 Mbit/s G.703 interfaces (L2M-G703)

4DF64-G703 Four 64 Kbit/s co-directional G.703

interfaces, with E/M signalling (DF64)
 SAFN
ARCHITECTURE: Repetitive units (2)

Board Description

2N64-V11 Two Nx64 Kbit/s V11 / V35 / V36 interfaces

(Nx64K)
5DCE-V28 Five X.20bis/V.28 and X.21bis/V.28 low rate
interfaces (DCE-V28)
8CLG Eight 2/4 wires voice interfaces, with E/M
signalling (CLG)
10PLAT Ten FXS interfaces (PLAT)

10PLAC Ten FXO interfaces (PLAC)

3DCE/2PLAT/2CLG Three X.20bis/V.28 and X.21bis/V.28 low

rate data interfaces (DCE-V28), two FXS
interfaces (PLAT) and two 2/4 wires voice
interfaces, with E/M signalling (CLG)
LAN-ETH Four Ethernet 10/100BT interface (ETH).
The unit realize also the IP routing function
 SAFN
ARCHITECTURE: Optional units

Board Description

TELETAXE The unit is a subassembly of the 10PLAC

unit. Its equipping allows the management of
the teletaxe pulses (12 KHz / 16 KHz). Each
subassembly allows the management of the
teletaxe pulses on 5 FXO (PLAC) interfaces
8I/O The unit is a subassembly of the US unit. Its
equipping allows the management of 8
digital inputs and 8 digital outputs from/to
external devices
SUB-V11 The unit is a subassembly of UC unit. Its
equipping allows the management of DCN
interface with electric interface in
compliance with ITU-T V.11 (it also allows
the management of more equipments with
Point-Multipoint electrical connection)
 SAFN
ARCHITECTURE: Stand-alone units

Board Description

REG_SHDSL SHDSL Repeter

To correctly work on copper links, whose
length exceeds the capacity of the g.shdsl
Line Terminal, a g.shdsl Repeter can be
provided. The Repeter provides the
possibility of both local and remote power
supply.
Up to 4 SHDSL Repeters (also with remote
power supply).
 SAFN
INTERFACES

To increase the flexibility in the use of the equipment, the cards are the same both for the use as
tributaries and as aggregates.

As Line Terminals (to cover a given distance on copper or fibre optics) are available:

fibre optics 155 Mb/s (STM-1).

g.shdsl interface to cover, with a ≤ 2 Mb/s stream, the links on one or two copper pair (SHDSL).

As Exchange Terminals (to connect the equipment to higher order multiplexer) are available:

2 Mb/s G.703 interface (L2M-G703).

A mixed equipping of Line Terminals (SDH / DSL) is possible inside the same SAFN.

The Line Terminals integrated in the equipment directly access to the cross-connection matrices.
So to transmit voice and data on links in copper of fibre optics doesn’t require the use of Exchange
Terminals.
 SAFN
INTERFACES (1)
TM-1 / ADM-1 (155 Mb/s Optical Fiber) 1/2

The board TM-1 / ADM-1 manages one / two STM-1 streams on a monomode or multimode fibre.
To correctly work both on monomode and multimode fibre, and to work with different power-
budget, the optical interfaces are provided with pluggable optical tranceivers (SFP transceivers).
The optical streams provides the transport of the 63 VC12 of the STM-1 frames (with a full cross
connection of all these VC12).

The board manages the mapper of up to 16 E1 streams:

8 E1 streams are managed as plesiochronous transport, with 2 Mb/s G.703 physical interfaces
directly on the TM-1 / ADM-1 board.

8 E1 streams are managed as synchronous PCM, used by the internal switching-circuit in the
Access functions.
 SAFN
INTERFACES (2)
TM-1 / ADM-1 (155 Mb/s Optical Fiber) 2/2

- Transmission support : mono-mode fibre-optic (10/125µm)

- Wave length : 1310 nm and 1550 nm.
- Payload : 155 Mb/s (63 2 Mb/s streams)
- Optical connectors : LC.
- Safety limits of opto-transmitter : in compliance with IEC 825.

SFP Fibra Potenza Sensibilità Attenuazione Lunghezza Portata

in Tx in Rx garantita d’onda
(dBm) (dBm) (dB) (nm) (Km)

S-1.1 SM ≥- 5 - 34 ≥ 29 1550 80
L-1.1 SM ≥- 5 - 34 ≥ 29 1310 40
L-1.2 SM ≥ -15 - 31 ≥ 16 1310 20
I MM ≥ -20 - 31 ≥ 11 1310 2
 SAFN
INTERFACES (3)
SHDSL

It manages a ≤ 2 Mb/s stream on one or two copper pairs:

- g.shdsl standard : ETSI TS 101 524
- Transmission support : 1 or 2 copper pairs
- Transmission mode : Full duplex with echo canceller
- Line code : 16PAM
- Transmission bit rate : from 384 Kb/s to 2048 Kb/s
- Nominal impedance : 135 Ω (balanced)
- Transmission power : +13,5 dBm
- Attenuation @ Ft : see table below
- Remote power supply : Possibility to supply a repeter by remote

Baud rate (Kb/s) Attenuation (dB) / Ft (Khz)

384 50 / 150
512 44 / 150
768 36 / 150
1024 32 / 150
1280 29 / 150
1536 26 / 150
2048 24 / 200

SHDSL interface manages also adaptative baud-rate.

 SAFN
INTERFACES (4)
L2M-G703 (2 Mb/s G.703)

It manages a 2 Mb/s stream in compliance with ITU-T G.703, both with line impedance of 75 Ω and
line impedance of 120 Ω.
It is an exchange terminal: the receiver can support line attenuations ≥ 6 dB at 1024 kHz.
The signal handling is in compliance with what specified in ITU-T G.704, G.706 and G.732.
The interface is transparent to the signals multiplexed in it at 64 Kb/s level, except the “TS0” time
slot.

Nx64K (Nx64 Kb/s V.11 / V.35 / V.36)

It manages an high rate data channel in compliance with ITU-T X.21 or X.21 bis.
By means of software programming, a scrambler can be inserted on the data in transmission (circuit
103) in compliance with ITU-T V.38; at the same way, the correspondent descrambler circuit can be
inserted on the data in reception (circuit 104).
The data stream at Nx64 Kb/s interface, with N between 1 and 32 and selectable via software, is
divided in N octets; these will be located in the N programmed timeslots of the 2 Mb/s G.704
aggregate stream, maintaining the correct sequence.
By means of Hw presetting, it is possible to work, as electric interface, in three different modalities:
- X.21bis / V.35 access
- X.21bis / V.36 (RS-449 / RS-530) access
- X.21 / V.11 access
 SAFN
INTERFACES (5)
DCE-V28 (low rate data channel X.20bis/V.28 ed X.21bis/V.28)

It manages a data channel with bit rate from 1.2 Kb/s to 19.2 Kb/s in compliance with ITU-T
X.20bis/V.28 and X.21bis/V.28, with sub-rate frame in compliance with ITU-T X.50 div. 3.
Channel bit rate (both synchronous and asynchronous): 1.2, 2.4, 4.8, 9.6, 14.4 and 19.2 Kb/s

For the management of the asynchronous channels, the ITU-T V.14 is used (to reduce the
throughput the management of “break signal” is not implemented).

DF64 (64 Kb/s codirectional G.703, with E/M signalling )

It manages a 64 kb/s stream, in compliance with ITU-T G.703 co-directional, with two E/M
signallings.
The E/M signalling is inserted in “TS16” timeslot, as associated signalling with two ways for direction
(“a” and “b” bits).

ETH (Ethernet 10/100BT interface )

Interface to LAN Ethernet 10/100BT.

 SAFN
INTERFACES (6)
CLG (2/4 wires, with E/M signalling )

It manages a voice channel, on the lines with two or four wires, with two E/M signallings.
The voice signal is converted from analogue to digital, and vice-versa, according to the “A” law of
ITU-T G.711.
The E/M signalling is inserted in “TS16” timeslot as associated signalling with two ways for each
direction (“a” and “b” bits).

The following parameters can be programmed:

- Outcoming signal level (4 wires): + 4 dBr ÷ -11.5 dBr, step 0.5 dB
- Incoming signal level (4 wires): + 1.5 dBr ÷ -14 dBr, step 0.5 dB
- Outcoming signal level (2 wires): - 2 dBr ÷ -11.5 dBr, step 0.5 dB
- Incoming signal level (2 wires): + 7.5 dBr ÷ -8 dBr, step 0.5 dB

By means of hardware presettings, it is possible to program each single interface, independently,

as 2 or 4 wires.
 SAFN
INTERFACES (7)
PLAT (FXS interface)

It manages, on 2 wires line, BCA phones with decadic and multi-frequency selection, replying the
functions executed by the user connection of the private or public exchange.
The voice signal is converted from analog to digital, and vice-versa, according to the “A” law of
ITU-T G.711.
The signalling is transported in “TS16” timeslot, as associated signalling with two ways for each
direction (bit “a” and “b”).
The signalling coming from phone side (engagement) is inserted in bit “a” towards the cross-
connection matrix. The signalling coming from the cross-connection matrix on bit “a” and “b” are
returned towards the phone as “ring” and “teletaxe pulses” (12 KHz / 16 KHz).
The phone side interface generates the ringing voltage.

In FXS-FXS (PLAT-PLAT) modality (direct call), this interface provides also to the “ring” timing (1
second / 4 seconds), towards the phone, in presence of the active “a” signalling bit, coming from
the cross-connection matrix cross-connection matrix.

The following parameters can be programmed:

- Outcoming signal level: 0 dBr ÷ + 2 dBr, step 0.5 dB
- Incoming signal level: - 8 dBr ÷ 0 dBr, step 0.5 dB
 SAFN
INTERFACES (8)
PLAC (FXO interface)

It manages, on 2 wires lines, the user connection of the private or public exchange, replying the
functions executed by BCA phone.
The voice signal is converted from analog to digital, and vice-versa, according to the “A” law of
ITU-T G.711.
The signalling is transported in “TS16” timeslot, as associated signalling with two ways for each
direction (“a” and “b” bits).
The signalling coming from exchange side (ring and teletaxe) are inserted in bit “a” and “b” towards
the cross-connection matrix. The signalling coming from the cross-connection matrix on bit “a” is
returned towards the exchange as “engagement”.

The following parameters can be programmed:

- Outcoming signal level: -10 dBr ÷ + 1.5 dBr, step 0.5 dB
- Incoming signal level: - 7 dBr ÷ + 4.5 dBr, step 0.5 dB
 SAFN
SERVICE INTERFACES (1)
Synchronization interface

If equipped with US unit, SAFN is provided with one synchronisation interface, in compliance with
ITU-T G.703, by means of which the synchronisation of the equipment with a 2048 KHz signal is
possible.

Management interfaces

SAFN is provided with 10BaseT management interface. If equipped with US unit, SAFN is provided
also with two management interfaces, generally one dedicated to a local operator (LT interface)
and one dedicated to a management centre (DCN interface).

Alarms interface

If equipped with US unit, SAFN is provided with an alarms parallel interface. The alarm interface
has contacts which reports the network and the equipment summary alarms, to external
supervision systems (ground = alarm). SAFN, furthermore, makes available a ground contact,
galvanically insulated, to report the alarm of power supply missing (implement by a drop relay).
 SAFN
SERVICE INTERFACES (2)
I/O interface

If equipped with US unit, provided with 8I/O subassembly, SAFN can accept signalling/alarms
(coming from external devices in the form of opening or closing of contacts) and can send
commands (to external devices in form of opening or closing of contacts). 8I/O subassembly can
manage up to 8 senders and 8 returners. The state of the contacts to the external devices
(commands) is commanded by the management system. The state of the contacts coming from the
external devices (signallings) is detected by the management system. Each single signalling can
also be configured as “alarm” (identifying then a “work condition” and a “stand-by condition”) and
then managed in the alarms table.
 SAFN
Power supply (1)

Board I (+5V) I (+12V) I (-12V) I (-24V) I (-54V) I (48V)

(mA) (mA) (mA) (mA) (mA) (mA)
UC 400 - 15 - - -

US 100 15 30 - - -

TM-1/ADM-1 1800 - - - - -

2LSHDSL4w 1100 - - - - -

2LSHDSL 1000 - - - - 550 (*)

4L2M-G703 500 - - - - -

2L2M-G703 380 - - - - -

4DF64-G703 250 - - - - -

(*) Remote Power Supply

 SAFN
Power supply (2)

Board I (+5V) I (+12V) I (-12V) I (-24V) I (-54V)

(mA) (mA) (mA) (mA) (mA)
2N64-V11 300 10 15 - -

5DCE-V28 180 15/60 (**) 80/30 (**) - -

8CLG 250 25 25 - -

10PLAT 250 20 35 300/30 (**) 240(24 (**)

10PLAC 250 30 30 - -

3DCE/2PLAT 250 20/45 (**) 60/30 (**) 60/6 (***) 48/5 (***)
/2CLG
LAN-ETH 1000 - - - -

(**) V.28 Criteria

(***) ring / conversation
 SAFN

SAFN
SDH Add-Drop and Access
Multiplexer

Selta Network Management System

(SNMS)
 SAFN
SNMS

Fault monitoring
Provisioning
Performances monitoring
Software updating
Links management

OSS integration (SNMP)

Embedded Operation Channel (EOC)

HP “Open View” Platform

 SAFN
SNMS
SNMS works on PC with Windows 95/98/NT/2000/XP.
It’s a management system, with graphical interface that makes easy and intuitive its use, that
realize:

- Fault and signal monitoring.

- Provisioning (configuration management).
- Performance monitoring.
- Software updating (updating of all the software and gate-array).
- Link management (circuit-viewer and circuit-manager).

To allow the management of SAFN using a non-proprietary management system (able to manage
different equipment from different providers) :

- The ‘Management Information Base’ (MIB) is available in a syntax compliance with IETF SMI.
- An SNMP agent is implemented on SAFN, to use a standard application protocol.
 SAFN
SNMS: EOC
SAFN can manage a service channel (EOC = Embedded Operation Channel) on the streams that
connect the different equipments in a network.

SNMS uses this EOC to work on all the SAFNs of a complex and meshed network (all the
operations on the local SAFN are so also possible on every SAFNs).
To centre this target it is necessary to configure a service network providing an EOC path between
every node interested by the operations and the node connected to the SNMS.

SAFN can route IP packet from the EOC channel and the LT and DCN ports; to do this the only
board required is the UC .
It’s possible however to enhance routing performance and capability adding the LAN-ETH board to
the equipment.
 SAFN
SNMS: Point-to-Multipoint EOC
This network topology has the advantage of a fast answer (every network node is directly polled by
the management centre using a Point to Multipoint connection, so the access rate to a network
node does not depend from the location of the node itself in the network).

Usually in Point-to-Multipoint solution (that requires a tree topology) there are, however, some
constrains:
- The management centre must be in a fixed location, chosen during the network configuration
(to move this centre the Point-to-Multipoint connections must be reconfigured).
- The polling from more management centres is not allowed.
- The automatic re-routing on link failure is not allowed.
- Spontaneous signallings (TRAPs) from the network nodes to the centre are not allowed
(the TRAPs must be excluded and the centre must manage a polling to detect the alarms).

Selta’s solution for the Point-to-Multipoint EOC protection (based on a pilota criterion) has the
advantage of the fast answer and no constraints related to the Point-to-Multipoint topology.
 SAFN
SNMS: Point-to-Multipoint EOC
Standard solution
P
Advantages : SAFN
- Fast answer in EOC C SAFN

Detriments :
- Only one NMS
- Failure restore unmanaged
- Traps unmanaged
P
SAFN
C
SAFN
SAFN SAFN
P C P
P

Network
Management
System
= EOC
C = Central in Point to Multipoint
P = Peripheral in Point to Multipoint
SAFN
 SAFN
SNMS: Point-to-Multipoint EOC
SAFN solution
0
Advantages : P
SAFN
- Fast answer in EOC C SAFN
P 1
- NMS mobile (More NMS)
- Channel protection (Failure restore)
0
Detriments : 0
1
- Traps unmanaged 0
P P
SAFN 0
C
1 SAFN 0 C P 0
SAFN SAFN
P 1 1
P P

Network 0
Management
System 0 = EOC (Active)
1 0
= EOC (backup)
C = Central in Point to Multipoint
P = Peripheral in Point to Multipoint
SAFN
C P 0/1 = Pilota Criterion
 SAFN
SNMS: Point-to-Multipoint EOC
SAFN solution 0
P
Advantages : SAFN
- Fast answer in EOC P SAFN
1
- NMS mobile (More NMS) C
- Channel protection (Failure restore)
1
Detriments : 0
0
- Traps unmanaged 0
P P
SAFN 1
P
0 SAFN 0 P P 0
SAFN SAFN
P 0 1
C C

1 = EOC (Active)
0 0
= EOC (backup)
C = Central in Point to Multipoint
P = Peripheral in Point to Multipoint
Network SAFN
Management 0/1 = Pilota Criterion
System
 SAFN
SNMS: Point-to-Multipoint EOC
SAFN solution
0
Advantages : P
SAFN
- Fast answer in EOC C SAFN
P 1
- NMS mobile (More NMS)
- Channel protection (Failure restore)
0
Detriments : 0
1
- Traps unmanaged 0
P P
SAFN 0
C
1 SAFN 0 C P 0
SAFN SAFN
P 1 1
P P

Network 0
Management
System 0 = EOC (Active)
1 0
= EOC (backup)
C = Central in Point to Multipoint
P = Peripheral in Point to Multipoint
SAFN
C P 0/1 = Pilota Criterion
 SAFN
SNMS: Point-to-Multipoint EOC
SAFN solution
1
Advantages : P
SAFN
- Fast answer in EOC C SAFN
P 1
- NMS mobile (More NMS)
- Channel protection (Failure restore) 1
1
Detriments :
1
- Traps unmanaged 1
P P
SAFN 0
C
1 SAFN 1 C P 1
SAFN SAFN
P 1 1
P P

Network 0
Management
System 1 = EOC (Active)
1 0
= EOC (backup)
C = Central in Point to Multipoint
P = Peripheral in Point to Multipoint
SAFN
C P 0/1 = Pilota Criterion
 SAFN
SNMS: Point-to-Multipoint EOC
SAFN solution
0
Advantages : P
SAFN
- Fast answer in EOC P SAFN
C 1
- NMS mobile (More NMS)
- Channel protection (Failure restore) 1
1
Detriments :
1
- Traps unmanaged 0
P P
SAFN 0
C
1 SAFN 1 P P 0
SAFN SAFN
P 1 1
P C

Network 0
Management
System 1 = EOC (Active)
1 0
= EOC (backup)
C = Central in Point to Multipoint
P = Peripheral in Point to Multipoint
SAFN
C P 0/1 = Pilota Criterion
 SAFN
SNMS: Point-to-Point EOC
This network topology has the advantage to allow spontaneous signallings (TRAPs) from network
nodes to the centre, but it is slower in the answer because of the packet retransmission in every
node (routing function).

More centres and alternative paths are managed using the standard solutions in a packet network
(routing tables, dynamic routing, etc.).

With SAFN (both Point-to-Multipoint and routing capability) it is possible to use mixed solutions for
EOC (Point-to-Multipoint connections, using polling from SNMS, and Point-to Point connections,
using routing).
It is possible to report to the management centre also other equipments, geographically located in
the same place of a SAFN, but without any carrier towards the network (service networks with
extensions).
 SAFN
SNMS: Point-to-Point EOC
SAFN routing capability
Advantages : SAFN
- Traps managed SAFN
- More NMS
- Failure restore managed

Detriments :
- Slow answer in EOC

SAFN

SAFN
SAFN SAFN

Network
Management
System

= EOC between UC

Network = 64 Kb/s as WAN for router

SAFN
Management = IP Router function
System
 SAFN
SNMS: Mixed service network
RS485
DCN
P
Other equipment V11 V11 SAFN
With TCP/IP SAFN C SAFN

Other equipment
With TCP/IP
Network
DCN Management
System
SAFN

SAFN
SAFN SAFN

V11 = SUB-V11 optional unit

= EOC between UC
= 64 Kb/s as WAN for router
SAFN SAFN
RS232
LT DCN
= IP Router function
 SAFN
SNMS: Other features
More exclusive SNMS Access points
A solution to increase the
dependability of the Network SAFN SAFN
Management System

SAFN
SAFN SNMS
Access point

SNMS
SAFN SAFN
Access point SAFN
SAFN

SAFN

IP Network

Network
Management
System
 SAFN
SNMS: Other features
More simultaneous SNMS Access points
A solution to reduce the polling time
SAFN SAFN

SAFN
SAFN SNMS
Access point

SNMS
SAFN SAFN
Access point SAFN

Link not used for EOC

SAFN
(recovered on other
SAFN link failure)

IP Network
Red and Green
simultaneous pollings

Network
Management
System
 SAFN
SNMS: Alarms classification
Alarm type

- COMMUNICATION (NETWORK alarms):

These alarms are related to problems in the link (ex. Loss of signal, ecc…). Therefore, they are
normally caused by anomalies and noises external to SAFN.
- EQUIPMENT (EQUIPMENT alarms):
These alarms are caused by anomalies internal to SAFN (ex. Power supply problems, generic
failure to hardware components, missing of configured cards, ecc...).
- PROCESSING (SOFTWARE alarms):
These alarms are related to anomalies in the software management (ex. download errors,
mismatch of database versions, ecc...).

Alarm severity

- URG (it includes the CRITICAL and MAJOR categories, as defined in M.3100):
This alarm causes a service loss; therefore, an immediate action is required.
- NURG (it includes the MINOR and WARNING categories):
This alarm does not involve the service; however, a corrective intervention is required to avoid
alarms of higher severity.

Note: Some COMMUNICATION alarms are classified as IND, instead of URG or NURG, when
they report the indication of an alarm detected on the remote equipment.
 SAFN
SNMS: Loopbacks
External loopback

It consists in closing the circuits in input from the (user or network) interface on the circuits in
output towards (user or network) interface.

Internal loopback

It consists in closing the streams from the cross-connection matrix (from inside the equipment) on
the streams towards the cross-connection matrix (towards the inside of the equipment).

The state of the loopbacks can be read both from the local terminal and from the management
centre.
 SAFN

SAFN
SDH Add-Drop and Access
Multiplexer

Applications
 SAFN
Applications: Transport & Access

SDH ring
(MSP and SNCP protections managed by SAFNs)

SAFN SAFN
ADM ADM
(Transport) (Transport)
Plesyochronous E1 Plesyochronous E1

MUX MUX
(Access) (Access)

Voice, Video and Data Voice, Video and Data

(TDM and IP users) (TDM and IP users)
 SAFN
Applications: PDH branch from SDH network

SDH network
SAFN SAFN
(ADM) (ADM)

May be
the same
equipment PDH network

SAFN xDSL SAFN xDSL SAFN

(MUX) (MUX) (MUX)

Both TDM
and IP
LAN LAN
RTU RTU RTU
H.261
mpeg Remote video
Audio broadcast monitoring (TDM)

Remote video
monitoring (IP)
 SAFN
Applications: PBX/RTU in Railways and Pipeline
Primary link on pipeline (STM-1)

SAFN SAFN SAFN External

PBX
SCADA RTU
RTU
LAN
External

Branch (XDSL)
PBX

g.shdsl

SAFN

RTU
LAN
 SAFN
Applications: Service Telephone System / RTU
Primary link (STM-1)

SAFN SAFN SAFN External

PBX
SCADA RTU
RTU
LAN

Branch (XDSL)
Telephone System
CO

g.shdsl
Operator 1

g.shdsl
Operator 2 SAFN
SAFN

Operator 3 RTU
LAN

SIP Phone
 SAFN
Applications: Protected Point-Multipoint

Dynamic role for Central and Peripheral in point-to-multipoint connections

SAFN SAFN

SAFN
SAFN

SAFN SAFN
SAFN
Point-Multipoint
Root SAFN

SAFN

SCADA
 SAFN
Applications: Protected Point-Multipoint

Dynamic role for Central and Peripheral in point-to-multipoint connections

SAFN SAFN

SAFN
SAFN

SAFN SAFN
SAFN
Point-Multipoint
Root SAFN

SAFN

SCADA
 SAFN
Applications: Protected Point-Multipoint (disaster recovery)

SAFN SAFN

SAFN
SAFN

SAFN SAFN
SAFN
Normal Point-
Multipoint Root SAFN

SAFN

Emergency
SCADA
SCADA (Disaster
(Normal recovery)
Central CE)
 SAFN
Applications: Protected Point-Multipoint (disaster recovery)

SAFN SAFN

SAFN
SAFN Emergency
Point-Multipoint
Root

SAFN SAFN
SAFN
SAFN

SAFN

Emergency
SCADA
SCADA (Disaster
(Normal recovery)
Central CE)
 SAFN
Applications: Protected Point-Multipoint (example with MSP)

Multiplex
Dynamic Central CE
Section
Protection

Cable 1

SAFN SAFN SAFN SAFN SAFN

SCADA

SAFN SAFN SAFN SAFN SAFN

Emergency Cable 2
SCADA RTU RTU RTU RTU RTU

Peripheral CE
 SAFN
Applications: Protected Point-Multipoint (example with MSP)

Multiplex
Dynamic Central CE
Section
Protection
Cable 1
Bandwith / 2
SAFN SAFN SAFN SAFN SAFN
SCADA

SAFN SAFN SAFN SAFN SAFN

Emergency
SCADA Cable 2
RTU RTU RTU RTU RTU

Peripheral CE
 SAFN
Applications: Protected Point-Multipoint (example MSP and SNCP)

Multiplex
Dynamic Central CE
Section
Protection
Cable 1
Bandwith / 2
SAFN SAFN SAFN SAFN SAFN
SCADA

SAFN SAFN SAFN SAFN SAFN

Emergency Cable 2
SCADA RTU RTU RTU RTU RTU

Peripheral CE
 SAFN
Applications: Protected Point-Multipoint (example MSP and SNCP)

Meshed (ring) topology with Sub-Network Connection Protection

2 controdirectional rings

SAFN SAFN SAFN SAFN SAFN

SCADA

SAFN SAFN SAFN SAFN SAFN

Emergency
SCADA RTU RTU RTU RTU RTU
 SAFN
Applications: Protected Point-Multipoint (recovery)

SCADA recovery with

dynamic Central CE
Link recovery
with MSP

SAFN SAFN SAFN SAFN SAFN

SCADA

SAFN SAFN SAFN SAFN SAFN

Emergency
SCADA RTU RTU RTU RTU RTU

Connection recovery
with SNCP in the ring
 SAFN
Applications: Digital Teleprotection
SDH

Power Line

SAFN SAFN
Distance Distance
Protection Protection

Really low transmission delay (< 2ms)

for Digital Teleprotection applications
Digital Digital
Teleprotection Teleprotection

Other services: Other services:

- SCADA and RTU - SCADA and RTU

- PBX extension (remote phone) - PBX extension (remote phone)
- Video monitoring - Video monitoring
- Connections between PBX - Connections between PBX
 SAFN
Applications: Private Mobile Radio (PMR)
Mobile

Analog Analog Analog

Analog Analog Up-link channel: Analog
Radio Radio Radio
Radio Radio SDH, Radio link, Radio
MUX with static
etc.
Cross-Connections

SAFN SAFN SAFN

MUX with dinamic

Connections PTP
and conference
CO
SAFN, with DSP capability, may be used also as
Concentrator (digital switch in Rx and digital
SAFN PTMP in Tx).

SAFN, with VoIP gateway capability, can work

directly on the LAN (IP-Phone) without FXS
Conc. interfaces.
Solution suitable also for digital radio link.

Analog Switch in Rx
Analog PTMP in Tx
 SAFN
Customers (1)

 RETE FERROVIARIA ITALIANA - RFI (Italy)

 SNAM RETE GAS (Italy, Switzerland, Austria, Germany and Tunisia)
 SNAMPROGETTI (Arabia Saudita, Tunisia)
 PHCN (Nigeria)
 DEDICOM A/S (Malesia Railways e TENAGA)
 NEC (Sri Lanka)
 SIRTI (Italy)
 PRAOIL (Italy)
 ENEL (Italy)
 BOMBARDIER (Portugal)
 A.E.M. Milano (Italy)
 ICS (Iran)
 ALSTOM POWER (Italy)
 ANSALDO SEGNALAMENTO (Italy)
 SAFN
Customers (2)

 CLEMESSY (Senegal)
 SFERIACOM (Italy)
 RFI METROPOLIS (Italy)
 SAFE COMMUNICATION LTD (Northern Ireland Railways)
 SELEDISON (Italy)
 SIELTE (Italy)
 SILIANI ELETTRONICA IMPIANTI (Italy)
 TRENITALIA (Italy)
 VENTURE (Italy)
 HAMDAM Trading EST (Middle East)
 IRTE (Italy)
 CIET (Italy)
 GRAPHTEL (Italy)
 ACEA Distribuzione (Italy)