Unimax MA-2025 User manual

1
Version 2.2
Unimax HSPA+ Ethernet Modem Router
MA-2025
User Manual
This manual is the sole and exclusive property of
Maxon Australia.
Not to be distributed or divulged without prior
written agreement.
+

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TABLE OF CONTENTS
CONTACT INFORMATION ............................................................................ 5
RF EXPOSURE COMPLIANCE ....................................................................... 6
Caution ................................................................................................. 6
REVISION HISTORY ................................................................................... 8
UNIMAX+ USER MANUAL............................................................................ 8
Disclaimers ........................................................................................... 9
1. INTRODUCTION............................................................................. 10
1.1 Overview ................................................................................. 10
1.2 Features .................................................................................. 10
2. HARDWARE ................................................................................... 11
2.1 Front Panel .............................................................................. 11
2.2 Side Panel (Left)...................................................................... 12
2.3 Side Panel (Right) ................................................................... 12
2.4 Back Panel ............................................................................... 12
3. SPECIFICATIONS........................................................................... 14
3.1 Mechanical............................................................................... 14
3.2 Environmental ......................................................................... 14
3.3 Electrical.................................................................................. 14
3.4 Hardware................................................................................. 14
4. PROTOCOLS & ENCRYPTIONS........................................................ 15
4.1 PPP (Point-to-Point Protocol) .................................................. 15
4.2 PPPoE (Point-to-Point Protocol over Ethernet) ........................ 15
4.3 DHCP (Dynamic Host Configuration Protocol).......................... 16
4.4 NAT (Network Address Translation or Translator) ................... 16
4.5 SNMP (Simple Network Management Protocol) ....................... 17
4.6 SNTP (Simple Network Time Protocol)..................................... 17
4.7 ICMP (Internet Control Message Protocol) .............................. 18
4.8 NAT-T ...................................................................................... 19
4.9 IKE .......................................................................................... 19
4.9.1 3DES .....................................................................................19
4.9.2 AES .......................................................................................19
4.9.3 MD5......................................................................................19
4.9.4 SHA ......................................................................................20
4.10 ISAKMP ................................................................................ 20

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4.11 ESM ...................................................................................... 20
4.12 RIP (Routing Information Protocol) ..................................... 20
4.13 VRRP (Virtual Router Redundancy Protocol) ........................ 21
5. WEB INTERFACE............................................................................ 22
5.1 Configuration Page Descriptions.............................................. 23
5.1.1 Status...................................................................................23
5.1.2 LAN .....................................................................................24
5.1.3 WAN....................................................................................25
5.1.4 Password ..............................................................................28
5.1.5 Log Out................................................................................28
5.2 Configuration Page Descriptions – Advanced........................... 29
5.2.1 Dynamic DNS ........................................................................29
5.2.2 DMZ ....................................................................................30
5.2.3 Port Forwarding......................................................................31
5.2.4 IP Filtering .............................................................................32
5.2.5 MAC Filtering.........................................................................34
5.2.6 VPN.....................................................................................35
5.2.7 Digital I/O Control ..................................................................36
5.2.8 Ping Tool...............................................................................38
5.2.9 SNMP ...................................................................................39
5.2.10 Routing ................................................................................40
5.2.11 VRRP ...................................................................................41
5.3 Configuration Page Descriptions – Administrator .................... 42
5.3.1 AT .......................................................................................42
5.3.2 Backup (Save/Reload) ............................................................42
5.3.3 System Logs ..........................................................................43
5.3.4 Time Zone .............................................................................45
5.3.5 System .................................................................................46
5.3.6 Upgrade Firmware..................................................................47
5.3.7 Save & Reboot ......................................................................48
6. OPERATION................................................................................... 49
6.1 Modem Router Mode ................................................................ 49
6.1.1 Setting Host PC’s Network Environment .......................................49
6.2 Bridge Mode............................................................................. 51
APPENDIX ................................................................................................ 56
Digital Input/Output ................................................................................ 56

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H/W Specifications.............................................................................56
Electrical Specifications ......................................................................56
Diagram ..........................................................................................56
Upgrade Firmware.................................................................................... 57
Factory Default Function .......................................................................... 58
Hard Reboot.....................................................................................58
Soft Reboot ......................................................................................58
SMS Commands ........................................................................................ 58
Commands ......................................................................................59
Requirements: .................................................................................... 59
WAN Connection – Signal Level ................................................................ 61
Setting SNMP Agent ................................................................................. 61
Environment .....................................................................................61
Unimax+ Configuration .......................................................................62
PowerSNMP Free Manager Configuration ...............................................62
Setting Unimax+ as a VPN Gateway or VPN Client ................................... 64
VPN Gateway...................................................................................64
VPN Client (L2TP over IPSec).................................................................66
VPN Client (IPSec)..............................................................................68
VPN Client (PPTP)...............................................................................69
Advanced Settings.................................................................................... 70
Connecting to a HUB..........................................................................70
Port Forwarding.................................................................................70
Setting DMZ Host .............................................................................72
Troubleshooting ....................................................................................... 74
Hardware Issues ................................................................................74
Software Issues ..................................................................................74

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CONTACT I NFORMATION
In keeping with Maxon's dedicated customer support policy, we encourage you to
contact us.
TECHNICAL:
Hours of Operation: Monday to Friday 8.30am to 5.30pm*
Telephone: [phone]
Facsimile: [phone]
Email: [e-mail] * Public holidays excluded
SALES:
Hours of Operation: Monday to Friday 8.30am to 5.30pm*
Telephone: [phone]
Facsimile: [phone]
Email: [e-mail] * Public holidays excluded
WEBSITE: www.maxon.com.au
Maxon has also added for the benefit of developers and integrators, a forum on our
website that can be accessed to discuss this product and/or technical matters in
relation to your applications. All questions raised within this portal will be answered.
FORUM: www.maxon.com.au/forum
ADDRESS:
Maxon Electronics Australia Pty Ltd
36a Gibson Avenue, Padstow
Sydney, NSW, Australia 2211
POSTAL ADDRESS
Maxon Electronics Australia Pty Ltd
Po Box 1, Revesby North,
Sydney, NSW Australia 2212

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RF EXPOSURE COMPLIANCE
The use of this device in any other type of host configuration may not comply with the
RF exposure requirements and should be avoided. During operation, a 20 cm
separation distance should be maintained between the antenna, whether extended or
retracted, and the user’s/bystander’s body (excluding hands, wrists, feet, and ankles) to
ensure RF exposure compliance.
Caution
Change or modification without the express consent of Maxon Electronics Australia Pty.
Ltd. voids the user’s authority to use the equipment. These limits are designed to provide
reasonable protection against harmful interference in an appropriate installation. The
modem is a transmitting device with similar output power to a mobile phone. This
equipment generates, uses, and can radiate radio frequency energy and, if not used in
accordance with instructions, can cause harmful radiation to radio communication.
Use only the supplied or an approved antenna. Unauthorized antennas, modifications,
or attachments could impair call quality, damage the device, or result in violation of RF
exposure regulations.
However, there is no guarantee that interference will not occur in a particular
installation. If the equipment does cause harmful interference in radio and television
reception, which can be determined by turning the equipment on and off, the user is
encouraged to try to correct the interference by one or more of the following
measures:
!Re-orient or relocate the receiving radio or TV antenna
!Increase the separation distance between the equipment and the receiver
!Contact Maxon Australia Technical Support for assistance.
Notes
The user is cautioned that changes or modifications not expressly approved by Maxon
Australia could void the warrantee.
Potentially Unsafe Areas
Posted Facilities: Turn off this device in any facility or area when posted notices

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require you to do so.
Blasting Areas: Turn off your device where blasting is in progress. Observe
restrictions and follow any regulations or rules.
Potentially Explosive Atmospheres: Turn off your device when you are in any
area with a potentially explosive atmosphere. Obey all signs and instructions.
Sparks in such areas could cause an explosion or fire, resulting in bodily injury or
death.
Areas with a potentially explosive atmosphere are often but not always clearly
marked. They include:
!fuelling areas such as gas or petrol stations
!below deck on boats
!transfer or storage facilities for fuel or chemicals
!vehicles using liquefied petroleum gas, such as propane or butane
!areas when the air contains chemicals or particles such as grain, dust or
metal powders
!avoid using the modem in areas that emit electromagnetic waves or
enclosed metallic structures e.g. lifts
any other area where you would normally be advised to turn off your engine

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REVISION HISTORY
Product
UNIMAX+ Industrial HSPA Ethernet Router
Model
EM-770W UNI
Document Type
PDF
Current Version Number
1
Status of the Document
Public Release
Revision Date
October 2012
Total Number of Pages
74
-Revision History
Level
Date
History
1.0
September 2012
Internal Release Version
1.1
October 2012
Public Release

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UNIMAX+ U SER M ANUAL
All data and information contained in or disclosed by this document are confidential
and proprietary information of Maxon Australia, and all rights therein are expressly
reserved. By accepting this material, the recipient agrees that this material and the
information contained therein are held in confidence and in trust and will not be used,
copied, reproduced in whole or in part, nor its contents revealed in any manner to
others without the express written permission of Maxon Australia. This information
provided in this document is provided on an “as is” basis.
In no event will Maxon Australia be liable for any damages arising directly or indirectly
from any use of information contained in this document. Information in this document is
preliminary and subjected to change without any notice.
Disclaimers
Life support – This product is not designed for use in life support appliances or systems where
malfunction of these products can reasonably be expected to result in personal injury.
Maxon Australia customers using or selling these products for use in such applications do so
at their own risk and agree to fully indemnify Maxon Australia for any damages resulting from
such application.
Right to make change - Maxon Australia reserves the right to make changes, without notice,
in the products, including circuits and software, described or contained herein in order to
improve design and/or performance.
This document is the sole and
exclusive property of Maxon
Australia. Not to be distributed or
divulged without prior written
agreement.
36A Gibson Ave
Padstow NSW 2211
Australia
URL: www.maxon.com.au

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1. INTRODUCTION
1.1 Overview
Unimax+ HSPA Ethernet Router performs data communication functions between wired-
LAN (Local Area Network) and wireless WAN (Wide Area Network) using HSPA cellular
station wirelessly. Unimax+ has various input voltage range that can support from 9~30
[VDC] which provides compatibility for platforms utilizing various industrial applications.
1.2 Features
!HSPA Wireless Module MC8705 PCI (21.1 Mbps downlink, 5.76 Mbps uplink)
!Frequency Bands - WCDMA 850/900/1900/2100 MHz
!10/100Mbps Ethernet Port
!Supports 10/100MHz Auto-Sensing
!32-bit RISC Network System on Chip
!System clock 250MHz (CPU) and 125MHz (BUS)
!3-Status LEDs indicator for device status
!External Antenna (FME Male)
!Periodic Reset
!Diagnostic Port
!Digital Inputs (Support 5V)
!Digital Outputs (Support 3.3V)
!L2TP/IPSec VPN
!Wide Range input Voltage range from 9 to 30[VDC]
CPU
NOR
Flash
(8MB)
SDRAM
(32MB)
USB 2.0
MODEM
Debug
Port
(14 Pin)
WAN UART
EJTAG
Ethernet
Port
&
Debug
JTAG
Cable
Mini PCI
Express
&
70pin
Connector
USB2.0
Switcher
GPIO
Interrupt
Digital Input
Module
(Support 5V)
GPIO Digital Output Module
(Changed Ext signal?)
Ext Connector
(Molex 5268)
GPIO
Status
LED
(2Ea)
SIM
Socket
Memory
BUS
Push S/W
(Factory reset) GPIO
Status
LED
(1Ea)
[Figure 1: System Block diagram]
This document is the sole and
exclusive property of Maxon
Australia. Not to be distributed or
divulged without prior written
agreement.
36A Gibson Ave
Padstow NSW 2211
Australia
URL: www.maxon.com.au

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2. HARDWARE
2.1 Front Panel
LED
DISPLAY
DESCRIPTION
Wireless Signal
Solid ON
Indicates signal is good (RSSI ≥-94 dBm)
1700ms ON and 1700ms OFF
Indicates signal is marginal (-95dBm ≥RSSI ≥
-115 dBm)
4900ms OFF and 100ms ON
Indicates signal is poor (RSSI ≤-115dBm)
4900ms ON and 100ms OFF
Indicates connection mode with no data
communication
100ms ON and 100ms OFF
Indicates connection mode with data
communication
Send/Receive
Data
Solid ON
Indicates connection mode with no data
communication
500ms ON and 500ms OFF
Indicates connection mode with data
communication
OFF
Indicates Unimax+ is not connected to
Internet
POWER
ON
Indicates main power is ON
OFF
Indicates main power is OFF
[Table 1: LED Display]

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2.2 Side Panel (Left)
1. Ethernet Port
2. Diagnostic Port (for debugging)
3. Digital I/O (Input: max 5VDC, Output: max 3.3VDC)
PIN NUMBER
DESCRIPTION
1 (VDD)
3.3V out
2 (D/I 1)
Digital input (max 5VDC)
3 (D/I 2)
Digital input (max 5VDC)
4 (D/O 1)
Digital output (max 3.3VDC)
5 (D/O 2)
Digital output (max 3.3VDC)
6 (GND)
GND
[Table 2: Digital I/O PIN Number]
4. Reset (Factory Reset)
5. Power (9 – 30VDC)
2.3 Side Panel (Right)
3G FME Male Antenna Connector
2.4 Back Panel
SIM Connector

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3. SPECIFICATIONS
3.1 Mechanical
Dimension
75.7 x 122.0 x 20.6 mm (with side bracket)
Weight
128g Approx
Housing Material
Aluminum
[Table 3: Mechanical Specifications]
3.2 Environmental
Operating Temp
- 10 ~ + 65 [°C]
Extreme Operating
Temp
- 20 ~ + 70 [°C]
Storage Temp
- 40 ~ + 90 [°C]
Humidity
5% ~ 95%
[Table 4: Environmental Specifications]
3.3 Electrical
DC Input Voltage
+ 9 ~ +30 [VDC]
Maximum Current
Under 1000 [mA] @ 12[VDC]
Internal Voltage
+1.8, +2.5 +3.3, + 3.8, + 5 [VDC]
Operating Current
Standby
PKT Data Connection
Under 250 [mA] @ 12 [VDC]
Under 430 [mA] @ 12 [VDC]
[Table 5: Electrical Specifications]
3.4 Hardware
ITEM
DESCRIPTION
Product
UNIMAX+ Industrial HSPA Ethernet Router
User MCU
32-bit Network Processor
Program Memory
8M Bytes (Flash)
Data Memory
32M Bytes (SDRAM)
Wireless Interface
HSPA WCDMA Module
HSPA Mini PCI Express Module MC8705 PCI
15-Pin Diagnostic Port
1 Test Port
Ethernet
1 Port 10/100Mbps Ethernet (only Full Duplex)
Digital I/O Port
2 Digital Inputs, 2 Digital Outputs
Display
3 Status LED’s
R-UIM
Support
[Table 6: Hardware Specifications]

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4. PROTOCOLS & ENCRYPTIONS
4.1 PPP (Point-to-Point Protocol)
PPP (Point-to-Point Protocol) is a protocol for communication between two computers
using a serial interface, typically a personal computer connected by phone line to a
server. For example, your Internet service provider may provide you with a PPP
connection so that the provider's server can respond to your requests, pass them on to
the Internet, and forward the requested Internet responses back to you. PPP uses the
Internet protocol (IP) and is designed to handle others. It is sometimes considered a
member of the TCP/IP suite of protocols. Relative to the Open Systems Interconnection
(OSI) reference model, PPP provides layer 2 (data-link layer) services. Essentially, it
packages your computer's TCP/IP packets and forwards them to the server where they
can actually be put on the Internet.
PPP is a full-duplex protocol that can be used on various physical media, including
twisted pair or fiber optic lines or satellite transmission. It uses a variation of High Speed
Data Link Control (HDLC) for packet encapsulation.
4.2 PPPoE (Point-to-Point Protocol over Ethernet)
PPPoE (Point-to-Point Protocol over Ethernet) is a specification for connecting multiple
computer users on an Ethernet local area network to a remote site via a modem. PPPoE
can be used to have an office or building-full of users share a common Digital
Subscriber Line (DSL), cable modem, or wireless connection to the Internet. PPPoE
combines the Point-to-Point Protocol (PPP), commonly used in dialup connections, with
the Ethernet protocol, which supports multiple users in a local area network. The PPP
protocol information is encapsulated within an Ethernet frame.
PPPoE has the advantage that neither the telephone company nor the Internet service
provider (ISP) needs to provide any special support. Unlike dialup connections, DSL and
cable modem connections are "always on." Since a number of different users are
sharing the same physical connection to the remote service provider, a way is needed
to keep track of which user traffic should go to and which user should be billed. PPPoE
provides for each user-remote site session to learn each other's network addresses
(during an initial exchange called "discovery"). Once a session is established between

16
an individual user and the remote site (for example, an Internet service provider), the
session can be monitored for billing purposes.
4.3 DHCP (Dynamic Host Configuration Protocol)
DHCP (Dynamic Host Configuration Protocol) is a communication protocol that lets
network administrators centrally manage and automate the assignment of Internet
Protocol (IP) addresses in an organization's network. Using the Internet Protocol, each
machine that connects to the Internet needs a unique IP address, which is assigned
when an Internet connection is created for a specific computer. Without DHCP, the IP
address must be entered manually at each computer in an organization and a new IP
address must be entered each time a computer moves to a new location on the
network. DHCP lets a network administrator supervise and distribute IP addresses from a
central point and automatically sends a new IP address when a computer is plugged
into a different place in the network.
DHCP uses the concept of a "lease" or amount of time that a given IP address will be
valid for a computer. The lease time can vary depending on how long a user requires
the Internet connection at a particular location. It's especially useful in education and
other environments where users change frequently. Using very short leases, DHCP can
dynamically reconfigure networks in which there are more computers than there are
available IP addresses. The protocol also supports static addresses for computers that
need a permanent IP address, such as Web servers.
4.4 NAT (Network Address Translation or Translator)
NAT (Network Address Translation or Network Address Translator) is the translation of an
Internet Protocol address (IP address) used within one network to a different IP address
known within another network. One network is designated as the insidenetwork and
the other as the outside. Typically, a company maps its local inside network addresses
to one or more global outside IP addresses and un-maps the global IP addresses on
incoming packets back into local IP addresses. This helps ensure security since each
outgoing or incoming request must go through a translation process that also offers the
opportunity to qualify or authenticate the request or match it to a previous request. NAT
also conserves on the number of global IP addresses that a company needs and it lets
the company use a single IP address in its communication with the world.

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NAT is included as part of a router and is often part of a corporate firewall. Network
administrators create a NAT table that does the global-to-local and local-to-global IP
address mapping. NAT can also be used in conjunction with policy routing. NAT can be
statically defined or it can be set up to dynamically translate from and to a pool of IP
addresses. NAT lets an administrator create tables that map:
!A local IP address to one global IP address statically
!A local IP address to any of a rotating pool of global IP addresses that a company
may have
!A local IP address plus a particular TCP port to a global IP address or one in a pool
of them
!A global IP address to any of a pool of local IP addresses on a round-robin basis
NAT is described in general terms in RFC 1631, which discusses NAT's relationship to
Classless Inter-domain Routing (CIDR) as a way to reduce the IP address depletion
problem. NAT reduces the need for a large amount of publicly known IP addresses by
creating a separation between publicly known and privately known IP addresses. CIDR
aggregates publicly known IP addresses into blocks so that fewer IP addresses are
wasted.
4.5 SNMP (Simple Network Management Protocol)
Simple Network Management Protocol (SNMP) is the protocol governing network
management and the monitoring of network devices and their functions. It is not
necessarily limited to TCP/IP networks.
4.6 SNTP (Simple Network Time Protocol)
Simple Network Time Protocol (SNTP) is a protocol that is used to synchronize computer
clock times in a network of computers. In common with similar protocols, SNTP uses
Coordinated Universal Time (UTC) to synchronize computer clock times to a millisecond,
and sometimes to a fraction of a millisecond.
Accurate time across a network is important for many reasons; even small fractions of a
second can cause problems. For example, distributed procedures depend on
coordinated times to ensure that proper sequences are followed. Security mechanisms
depend on coordinated times across the network. File system updates carried out by a
number of computers also depend on synchronized clock times. Air traffic control

18
systems provide a graphic illustration of the need for coordinated times, since flight
paths require very precise timing (imagine the situation if air traffic controller computer
clock times were not synchronized).
UTC time is obtained using several different methods, including radio and satellite
systems. Specialised receivers are available for high-level services such as the Global
Positioning System (GPS). However, it is not practical or cost-effective to equip every
computer with one of these receivers. Instead, computers designated as primary time
servers are outfitted with the receivers and they use protocols such as SNTP to
synchronize the clock times of networked computers. Degrees of separation from the
UTC source are defined as strata. A radio clock (which receives true time from a
dedicated transmitter or satellite navigation system) is stratum-0; a computer that is
directly linked to the radio clock is stratum-1; a computer that receives its time from
astratum-1 computer is stratum-2, and so on.
The term SNTP applies to both the protocol and the client/server programs that run on
computers. The programs are compiled by the user as an SNTP client, SNTP server, or
both. In basic terms, the SNTP client initiates a time request exchange with the time
server. As a result of this exchange, the client is able to calculate the link delay, its local
offset, and adjust its local clock to match the clock at the server's computer. As a rule,
six exchanges over a period of about five to 10 minutes are required to initially set the
clock. Once synchronized, the client updates the clock about once every 10 minutes,
usually requiring only a single message exchange. Redundant servers and varied
network paths are used to ensure reliability and accuracy. In addition to client/server
synchronization, SNTP also supports broadcast synchronization of peer computer clocks.
SNTP is designed to be highly fault-tolerant and scalable.
4.7 ICMP (Internet Control Message Protocol)
ICMP (Internet Control Message Protocol) is a message control and error-reporting
protocol between a host server and a gateway to the Internet. ICMP uses Internet
Protocol - IP data-grams, but the messages are processed by the IP software and are
not directly apparent to the application user.

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4.8 NAT-T
NAT-T (NAT Traversal in the IKE) is a method of enabling IPSec-protected IP datagram’s
to pass through a Network address translator (NAT). An IP packet is modified while
passing through a network address translator device in a manner that is incompatible
with Internet Protocol Security (IPSec). NAT-T protects the original IPSec encoded
packet by encapsulating it with another layer of UDP and IP headers. The negotiation
during the Internet key exchange (IKE) phase is defined in RFC 3947 and the UDP
encapsulation itself is defined in RFC 3948. Most major networking vendors support NAT-
T for IKEv1 in their devices. In Microsoft Windows XP with Service Pack 2 the feature can
be enabled.
4.9 IKE
Internet Key Exchange (IKE or IKEv2) is the protocol used to set up a security association
(SA) in the IPSec protocol suite. IKE uses a Diffie-Hellman key exchange to set up a
shared session secret, from which cryptographic keys are derived. Public key
techniques or, alternatively, a pre-shared key, are used to mutually authenticate the
communicating parties.
4.9.1 3DES
The earliest standard that defines the algorithm (ANS X9.52, published in 1998)
describes it as the "Triple Data Encryption Algorithm (TDEA)" — i.e. three operations
of the Data Encryption Algorithm specified in ANSI X3.92 — and does not use the
terms "Triple DES" or "DES".
4.9.2 AES
The Advanced Encryption Standard (AES) is an encryption standard adopted by
the U.S. government. The standard comprises three block ciphers, AES-128, AES-192
and AES-256, adopted from a larger collection originally published as Rijndael. Each
AES cipher has a 128-bit block size, with key sizes of 128, 192 and 256 bits,
respectively. The AES ciphers have been analyzed extensively and are now used
worldwide.
4.9.3 MD5
MD5 (Message-Digest algorithm 5) is a widely used cryptographic hash function
with a 128-bit hash value. As an Internet standard (RFC 1321), MD5 has been
employed in a wide variety of security applications, and is also commonly used to

20
check the integrity of files.
4.9.4 SHA
SHA stands for Secure Hash Algorithm. The three SHA algorithms are structured
differently and are distinguished as SHA-0, SHA-1, and SHA-2. The SHA-2 family uses
an identical algorithm with a variable digest size which is distinguished as SHA-224,
SHA-256, SHA-384, and SHA-512.
4.10 ISAKMP
ISAKMP defines the procedures for authenticating a communicating peer, creation and
management of Security Associations, key generation techniques, and threat
mitigation (e.g. denial of service and replay attacks). ISAKMP typically utilizes IKE for key
exchange, although other methods can be implemented.
4.11 ESM
Encapsulating Security Payload (ESP) is a member of the IPSec protocol suite. In IPSec, it
provides origin authenticity, integrity, and confidentiality protection of packets. ESP also
supports encryption-only and authentication-only configurations, but using encryption
without authentication is strongly discouraged because it is insecure. Unlike
Authentication Header (AH), ESP does not protect the IP packet header. However, in
Tunnel Mode, where the entire original IP packet is encapsulated with a new packet
header added, ESP protection is afforded to the whole inner IP packet (including the
inner header) while the outer header remains unprotected. ESP operates directly on
top of IP, using IP protocol number 50.
4.12 RIP (Routing Information Protocol)
RIP is a distance-vector routing protocol, which employs the hop count as a routing
metric. The hold down time is 180 seconds. RIP prevents routing loops by implementing
a limit on the number of hops allowed in a path from the source to a destination. The
maximum number of hops allowed for RIP is 15. This hop limit, however, also limits the
size of networks that RIP can support. A hop count of 16 is considered an infinite
distance and used to deprecate inaccessible, inoperable, or otherwise undesirable
routes in the selection process.
There are three versions of RIP. Unimax+ supports RIPv2.