Nortel Passport 4400 Series Reference manual

Passport 4400
Release 3.1
Introduction
Part Number 800-1982-31, Rev. A
February 1999

©1999 Nortel (Northern Telecom Company)
All rights reserved

Notice of Filing
Declaration of CE Conformance (for International sales)
A Declaration of CE Conformance is on file at the Nortel addresses shown below. The declaration lists the
models described in this manual. If the unit carries the CE mark, this declaration certifies that it meets the
specific EMC standards and safety (LVD) standards required for CE marking. If the product is a module, the
module is CE-compliant only if it is placed in a CE-marked base unit.
Any units not carrying the CE approval are not CE-compliant. Modules placed in these units may not meet
emission standards for CE compliance.
Notice
Specifications, tolerances, and design characteristics described in this manual are subject to change without
notice.
Trademark Notice
All names or trademarks are the true property of their respective owners.
Nortel Networks
4100 Guardian Street
Simi Valley, California 93063-3382
U.S.A.
[phone]

v
Contents
About this Document
Passport 4400 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Concepts and Applications — 1
Product Concept. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Bandwidth Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Voice Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Auto-learning Directory Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
The Data Network Address (DNA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
The Network Address Server (NAS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
The Network Address Client (NAC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
NAC Cache . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
IP/IPX Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
RFC 1490 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
Video Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Legacy Data Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
WAN Services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
The Passport Access Network Link (PANL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
Switched Virtual Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22
Backup Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
Scalability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26
Cascaded Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26
User Core Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27
Integrated Passport 4400/6400 Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28
Installation and Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
InstallTool. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31
Traffic Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31
Standards-Based Interoperability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-34
Ordering Codes — 2
Base Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
AC Base Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
DC Base Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Software and Document Packages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
WAN Interface Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
High Speed Data Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Legacy Data Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

vi
Analog Voice / Fax Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Analog Voice / Fax Interface Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Digital Voice Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
DRAM Memory Upgrade Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Flash Memory Upgrade Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Data Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Power Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Miscellaneous Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
User Manuals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Optional Modules — 3
Expansion Module Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Analog Voice Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Analog Voice Modules (AVM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Universal Analog Voice Module (UAVM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
T1/E1 and Digital Voice Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
T1 Voice Module (TVM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
E1 Voice Module (EVM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Digital Voice Module (DVM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Digital Voice Expansion Module (DVEM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
ISDN BRI Voice Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Compatible Marathon Voice Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
High-speed Data Module (HDM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Low-speed Data Service Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Road Map to the Product Documentation — 4
Accessing the Product Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
Master Table of Contents — A
ISDN BRI Manual - 800-1942-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Analog Voice Manual - 800-1943-31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
T1/E1 and Digital Voice Manual - 800-1944-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
CLI Reference Manual - 800-1950-31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-9
Hardware Installation Manual - 800-1951-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-17
Operator’s Manual - 800-1952-31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-20
InstallTool Release 2.0 Startup Guide - 800-1983-31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-22
Master Index — B

vii
About this Document
ThePassport 4400IntroductionandRoadMap Manualis designedtoassistthe
user in the understanding of the Passport 4400 and provide a road map for
accessing pertinent reference materials. Included in this manual are
descriptions of the Passport 4400 concepts and applications, model numbers,
optional modules, and a matrix correlating Passport 4400 descriptive and
operational information with the technical documentation which contains it.
Theappendixescontainamastertableofcontentsandamasterindex,providing
aroadmaptothetopicscoveredinall thePassport4400manuals.TheGlossary
contains a list of terms pertinent to the Passport 4400 and its networking
environment.
The following sections and their topics are contained in this manual:
•Section 1 - Concepts and Applications
•Section 2 - Ordering Codes
•Section 3 - Optional Modules
•Section 4 - Road Map to the Product Documentation
•Appendix A - Master Table of Contents
•Appendix B - Master Index
•Glossary - Glossary of Terms
Passport 4400 Series
The Passport 4400 series of multiservice access devices combines voice, fax,
video, IP and legacy data traffic over a choice of link options providing cost-
effective and easily managed networking solutions.
The Passport 4400 consists of the following base units:
• Model 4430 AC Base System
• Model 4450 160W AC Base System
• Model 4450 200W AC Base System
• Model 4450 160W DC Base System
• Model 4450 200W DC Base System
• Model 4455 160W AC Base System (with 68060 processor)
• Model 4455 200W AC Base System (with 68060 processor)

About this DocumentPassport 4400 Introduction and Road Map
viii
All base units include the chassis, power supply, fan unit, and Ethernet Base
Module.RefertoSection2,OrderingCodes,foracompletelistofmodelnumbers.
Model 4430 Model 4450 and 4455
Model 4450 and 4455
(160W Power Supply Unit)
(200W Power Supply Unit)

1-1
Concepts and Applications 1
This section discusses the keybenefits and applications of the Passport 4400 in
the areas listed below. (Special topics of interest that are included in the
subsections, are parenthetically noted.)
• Product Concept
• Bandwidth Management
• Voice Networks (NAS and NAC)
• IP/IPX Networks (RFC 1490 Direct Connect)
• Video Networks
• Legacy Data Networks
• WANs Services (PANL, SVCs and Backup Services)
• Scalability
• Cascaded Networks
• User Core Router
• Integrated Passport 4400/6400 Networks
• Installation and Service (InstallTool)
• Traffic Management
• Standards-Based Interoperability
Product Concept
ThePassport4400integratesvoice,fax,videoanddatatrafficoverasingleWAN
connection, eliminating the need for separate, parallel branch network
equipment and links.
Advanced bandwidth and voice technologies optimize bandwidth usage for
maximum throughput and voice quality.
Data is transmitted from different WAN sources using a unique frame relay-
based network link protocol, the Passport Access Network Link (PANL). PANL
fragmentslongframeswhenvoiceframesneedtobeinserted.Thisreducesboth
delay and delay variation. PANL then reassembles frames at the other end of
the link. The result is reduced WAN overhead and optional handling of voice
traffic.

Concepts and ApplicationsPassport 4400 Introduction and Road Map
1-2
PANL can link the Passport 4400 to another Passport 4400 or to the Passport
6400. In addition to PANL connections, the Passport 4400 can connect to third
party routers using frame relay PVCs and the RFC 1490 encapsulation
standard.
Network connections can be leased line or over a Public Frame Relay network.
And, the Passport 4400 protects its connections with a variety of backup
services.
The Passport 4400 Product Concept
Passport 4400
Device
Passport 4400
Device
Passport 4400
Device
Public Frame
Relay
PANL
PANL
Fax
PBX or
Key System
Video
ISDNDial
Back-up
Passport Access
Network Link
(PANL)
Codec
External Access
Router
RFC
1490 Passport 6400

Concepts and Applications Passport 4400 Introduction and Road Map
1-3
Bandwidth Management
The Passport 4400 utilizes ClearVoice, silence suppression and fax demodu-
lation technologies to reduce voice/fax bandwidth requirements as much as 96
percent, while delivering toll-quality voice. With both analog and digital voice/
fax offerings, the Passport 4400 delivers efficient integration networking on
WAN links ranging from 9.6 kbps to 1.544/2.048 Mbps.
Bandwidth Management Technologies
Passport 4400
Passport 4400
PBX
Voice is compressed from 64 kbps
(PCM) to toll-quality 8 kbps
ClearVoice. Silence Suppression
further reduces voice bandwidth
requirements.
Frame Relay support allows
connections to public frame
relay services, which can
offer cost savings when
comparedwithprivateleased
lines.
Tunnel Switched Virtual
Circuits (SVC) reduce the
number of Permanent Virtual
Circuits (PVCs) purchased
from a carrier.
Automatic fax demodulation
reduces fax bandwidth
requirements down to the fax
machine setting. For
example, a fax machine set
at 9.6 kbps requires only 9.6
kbps of bandwidth.
Synchronous (sync) data is
passed by sensing the
beginning and ending of sync
frames and sending only the
frame itself, not the idle
characters.
Dynamic Bandwidth
Allocation enables efficient
use of bandwidth.
Public Frame
Relay

Concepts and ApplicationsPassport 4400 Introduction and Road Map
1-4
Bandwidth Management Features
Feature Description Benefits
Voice Compression Delivers toll-quality voice at
8 kbps, based on the ITU
G.729 CS-ACELP voice
compression standard.
Frees up bandwidth for other
types of traffic.
Toll quality voice.
Voice interfaces have been
proven worldwide in over 200
country-specific environments.
Silence Suppression Allocatesbandwidth onlywhen
a speaker is talking. During
silent periods (40-60% of the
time), bandwidth is
dynamically allocated to other
voice, fax or data channels.
Virtually cuts in half the
amount of bandwidth used for
voice conversations, for more
efficient use of available
bandwidth.
Bandwidth Optimization Voice/data prioritization on
network link. Ensures application quality, with low delay for voice and
consistent service for mission-
critical data.
Dynamic Bandwidth
Allocation A channel gets bandwidth only atthepreciseinstantofactivity.
Whenever a channel is idle,
bandwidthisavailableforother
channels.
Provides efficient use of
bandwidth, unlike methods
such as Time Division
Multiplexing (TDM) which
reserve bandwidth whether or
not there’s activity.
End-to-end Switched Virtual
Circuit (SVCs) avoids tandem
transit bandwidth.
Tunneling Switched
Virtual Circuits (SVCs)
within a single PVC
All SVCs are tunneled within a
single PVC on a public FR
network. Each SVC can be
assigned a different class of
service and priority.
Reduces the number of frame
relay PVCs purchased from a
carrier.

Concepts and Applications Passport 4400 Introduction and Road Map
1-5
Voice Networks
The Passport 4400 provides simple, cost-effective voice networking with the
following key features.
• Users dial a directory number to establish a call. The end-user or
customer directory numbers do not need to be changed upon installing
a Passport 4400 network.
• Switched voice services means improved scalability. Calls are handled
on an end-to-end, single-logical-hop basis, with only a single
compression-decompression cycle to ensure the highest voice quality.
Voice/Fax Features
PANL Termination on
the Passport 6400 Access integration products like the passport 4400
fragment large data frames to
provide QoS for delay-
sensitive services like voice.
More efficient use of
bandwidth in large networks.
Automatic Fax
Demodulation Automatically detects fax signals.
Converts analog fax data back
to original digital form,
requiring 9.6 kbps or less in
one direction to send a fax.
Allows for more efficient use of
available bandwidth. Fax
signals cannot be
compressed, but
demodulating saves
bandwidth from the 64 kbps
standard transmission rate.
Supports connection of
virtually any fax machine. Fax
demodulation has been
proven worldwide in over 200
country-specific environments.
Feature Description Benefits
Integrated Networking Permits voice and fax traffic to
be integrated with video and
data traffic.
Eliminates monthly phone/fax
toll charges.
ClearVoice Voice
Compression Delivers toll-quality voice at 8kbps, virtually
indistinguishable from
uncompressed voice.
ClearVoice uses the ITU G.729
CS-ACELP voice compression
standard, optimized based on
years of Nortel telephony
service.
Customers reap the economic
benefits of integration without
compromising voice quality.
Frees up bandwidth for other
types of traffic while providing
toll-quality voice.
Voice interfaces have been
proven worldwide in more than
200 country-specific
environments.

Concepts and ApplicationsPassport 4400 Introduction and Road Map
1-6
Echo Canceller
Enable/
Disable Option
Disables internal echo
canceller when a more robust
system is used externally, e.g.,
longer echo path.
Improvesvoicequalityinoff-net
conference bridge applications
where echo cancellation
already exists.
Voice/Fax Switching Allows user to call/fax any user
on the Passport 4400 network.
Allows voice/fax calls to be
routed by Passport 4400
equipment directly.
Maintains voice quality, since a
PBX is not required for tandem
switching which would
introduce voice delay.
Industry-standard
analog (E&M, FXS,
FXO) and digital voice/
fax interface options
Supportsconnectionsto awide
variety of phone and fax
equipment, including
telephones, fax machines and
analog and digital PBXs.
Enables connectivity to most
common phones, fax
machines,analog/digitalPBXs,
and key telephone systems.
ISDN Basic Rate
Interface (BRI) option
with Q.SIG protocol
support.
Provides S/T electrical
connection with both NT (PBX
trunk or ISDN telephone) and
TE (PBX station or PSTN line)
modes.
Supports ETSI Q.SIG common
channel signaling protocol.
Overlap dialing is also
supported.
Uses Nortel Networks’ G.729-
based ClearVoice technology.
Provides ISDN BRI
connectivity to digital PBXs for
locations requiring few voice
ports (in increments of 2).
Support of the industry-
standard Q.SIG protocol
enables support of advanced
PBX features such as calling
the ID display and call
forwarding across a Passport
network.
Autocall Configurable option that
permits a user to be connected
automatically to a specific
destination whenever their
phone goes off-hook.
Simplifies calling, since no
numbers must be dialed.
Limits calling destinations
when needed for cost/security
reasons.
Used to support auto-ringdown
(ARD) applications used in
Financial Trader / Brokerage
Houses.
Country-Specific
Phone Characteristics Busy, dial and ringing tones are designed to sound
native
to the
specific country.
Greateruseracceptance,since
tones sound
natural
.
Feature (cont’d) Description (cont’d) Benefits (cont’d)

Concepts and Applications Passport 4400 Introduction and Road Map
1-7
Configurable Jitter
Buffer CompensatesforvariableWAN link delay characteristics by
changing the amount of time
data is queued in the output
portion of the voice port.
This function directly increases
or decreases the one-way
propagation delay in the voice
path. If set below 16 ms, it
reduces the tail length of the
echo canceller.
Improves voice quality in frame
relay networks, particularly
those with multiple links, which
may have voice breakup due to
public network congestion.
Analog Wink Start Wink Start is a Trunk protocol
used in Electronic Switching
Networks of PBXs. The PBX
collects full dialing information
and then makes a routing
choice (least-cost routing). It
waits for acknowledgment
(wink) from the next switching
unit before sending the dialing
information.
This is the most common PBX
tie trunk protocol.
The Wink Start protocol
simplifies corporate dialing
plans and supports Dual Tone
Multi-Frequency (DTMF)
dialing on tie trunks on
products such as Nortel
Networks’ Norstar or AT&T
Legend Hybrid Key Telephone
systems.
Transparent Common
Channel Signaling
(CCS) support
Transparently passes
"D-channel"signalingandforce
connects voice channels.
Enables all CCS signaling
formats to be supported.
Enables any digital PBX to
pass advanced call features to
other PBXs.
Hunt Groups Allows more than one voice
port to be assigned the same
extension number. Multiple
hunt groups may be defined.
Simplifiesthecallingprocedure
by allowing a user to dial an
extension number and
automatically get connected to
the first available voice port.
Without hunt groups, the user
would have to hang up and dial
another extension number, if
the first number was busy.
Voice/Fax Contention Allows multiple originating
voice/fax channels to contend
for connection to a smaller
number of receiving channels.
Reduces equipment and
networking costs at central
sites, since a dedicated voice/
fax channel is not required to
handle each originating
channel.
Feature (cont’d) Description (cont’d) Benefits (cont’d)

Concepts and ApplicationsPassport 4400 Introduction and Road Map
1-8
Hoot and Holler An always-up voice connection
method used in financial trader/
brokerage firms. Hoot and
Holler lines are not switched,
and are always off-hook.
Enables use of the Passport
4400 in financial trader/
brokerage applications.
Auto-Learning
Directory Server (NAC/
NAS)
Dynamically adds, deletes and
changes telephone numbers.
Contains a centralized
database of all telephone
numbers in the network.
Multiple servers may exist in
the network.
In a large network with both
4400 and 6400, NAC/NAS is
not used. Instead, Passport
6400 Voice Networking Call
Server (VNCS) provides
equivalent functionality.
Simplifies operations,
administration and
maintenance.
Provides added reliability.
Voice Switching Voice calls can be placed
between any two sites over the
Passport 4400 network. Users
dial the telephone number
which the Passport 4400
translates into a switched call
across the network using
network addresses.
Seamless connectivity with
Passport 4400-attached PBX
stations is provided, but call
routing is handled without any
need to transit through a
tandem PBX.
The telephone numbering plan
ofthenetworkdoesnotneedto
be changed when
implementing a Passport 4400-
based solution.
Eliminates the need for
dedicatedvoicechannelsatthe
branch and the host site,
reducing the number of voice
channels required and thus
reducing costs.
Eliminates the need for tandem
PBX equipment. Improves
voice quality by eliminating the
need for decompress and
recompress at each tandem
PBX.
Feature (cont’d) Description (cont’d) Benefits (cont’d)

Concepts and Applications Passport 4400 Introduction and Road Map
1-9
Voice/Fax Application
Fax
Fax
Passport 4400
PBX
PBX
Passport 4400
PANL
PANL PANL
Off-net
calls
PSTN
Frame
Relay
or Leased
Passport 4400
Fax
Passport 4400
PANL

Concepts and ApplicationsPassport 4400 Introduction and Road Map
1-10
Auto-learning Directory Server
The Data Network Address (DNA)
Individual Passport 4400 units are identified by their Data Network Address
(DNA). The DNA is assigned to each passport 4400 as a unique number, from
one to 15 digits in length. The DNA is then used to map services from one
Passport 4400 to another.
When networking between a Passport 4400 and a Passport 6400 switch, the
DNAs used for the Passport 4400s can be matched to the numbering currently
being used by the Passport 6400 network, following either standard x121 or
e164 formats.
The Network Address Server (NAS)
The passport 4400 Network Address Server (NAS) is a UDP/IP-based server
used to resolve the telephone number (DN) to Passport 4400 address (DNA)
mapping in the Passport 4400 network. Its database contains all of the DNs in
thenetwork.MultipleNASsmayexistinanetwork,forthepurposeofreliability,
scalability, and redundancy.
The voicecall is via an SVCdirectly between the originating Passport4400 and
thedestinationPassport4400. Once thedestinationaddress hasbeen resolved,
the NAS and NAC no longer participate in the call.
The NAS
• Resolves DN-DNA mappings using UDP/IP based protocol
• Dynamically populates the database with telephone numbers (DNs) as
they are added, deleted, or changed. This happens at the time a new
Passport 4400 is brought into the network and periodically once the
Passport 4400 is operational in the network.
• Dynamically removes "old" entries in the database
• Has a keep-alive protocol between the client and server
• Uses standard transport and network level protocols (TCP, UDP/IP)
• Is SNMP-managed
The Network Address Client (NAC)
TheNetworkAddressClient(NAC)isresidenton eachPassport4400 to resolve
DN-DNA requests. The NAC acts as a UDP/IP-based client with the ability to
locally cache the DN-DNA address mapping.
The NAC
• Receives egress table information from the voice application, and
registers the local DNs to known NASs in the network.

Concepts and Applications Passport 4400 Introduction and Road Map
1-11
• Relays DN-DNA requests, if not in its local cache, to the NAS. After
receiving the information from the NAS, it populates local cache with
the DN-DNA address mapping.
Voice Call Setup Using NAS
Note: In a large network with both Passport 4400s and 6400s, NAC/
NAS is not used. The Passport 6400 Voice Networking Call
Server (VNCS) provides equivalent functionality.
Example #:
234 5678
234 5679
Example #:
123 4567
123 4568
Network Address Server
1 : 4400 Initialization
2-4 : Voice Call Setup
15
34
2
5: Call Accept

Concepts and ApplicationsPassport 4400 Introduction and Road Map
1-12
NAC Cache
Every Passport 4400 maintains a local cache of DN-DNA mapping of the last
dialed telephone numbers. The local cache can be provisioned with up to 100
static entries of frequently dialed numbers. The purpose of the cache is to
minimizetheneedforaPassport4400tointeractwiththeNASorVNCS,saving
WAN bandwidth. When required to place an outgoing call, the Passport 4400
consults its local cache to obtain the DNA of the destination Passport 4400. If
it fails to resolve themapping with its local cache,it contacts theNAS or VNCS.
This process also considerably reduces the number of requests to the NAS or
VNCS.
Voice Call Setup Without NAS or VNCS
Note that the local cache has an upper bound on its size.
• The entries in the local cache will not get "aged-out".
• An entry will be removed if the Passport 4400 finds the destination
Passport 4400 unreachable. A destination is considered to be
unreachable, and the DNA non-existent, when a call fails to connect.
• If the local cache becomes full, room for a new entry is created through
the removal of the oldest entry or the least used entry. Note that
whenever an entry from the local cache is used to resolve matching, its
time is updated.
Network
Address Server
1 : Call Initialization
2 : Voice Call Setup
13
2
3 : Call Accepted
Example #:
123 4567
123 4568
Example #:
234 5678
234 5679