Archive for May, 2005

Functionality Differences between Microsoft Entourage 2004 and Microsoft Outlook 2001 for Mac

Friday, May 27th, 2005

Entourage 2004 has more options than Outlook 2001 but also does not communicate over MAPI but instead over WebDAV (OWA).

The Graphical User Interface (GUI) level changes are too numerous to review. A conversion from Outlook 2001 to Entourage 2004 requires retooling the workforce for the new application. Schedules, cached email addresses, signatures and other settings will be lost during the migration, but mail, contacts, calendars, to-do items and tasks should survive the migration.

Once common theme across the two is wasted resources. Outlook 2001 required OS 9 to run in OS X. Entourage 2004 requires Rosetta to run in OS X. Both waste a considerable amount of resources. However, both are the only supported clients for Microsoft Exchange for the Mac platform. One note about a possible Exchange 2007 upgrade is that you will loose your free CAL licensing for Entourage. If you read the EULA you no longer receive free Entourage licenses per CAL of Exchange 2007.

RepTools v2005 is Released: New Module, New Features, and Lower Price

Thursday, May 26th, 2005

Celebrating our 11th year of helping production and post-production companies operate more effectively, Three18 proudly announces the release of RepTools v2005.

Please accept my sincere thanks for choosing RepTools as your comprehensive job tracking, sales automation and media asset management tool over the past decade and please let me know what I can do to help comfortably move you into this feature rich and extremely capable version of RepTools 2005.

Password Security

Thursday, May 26th, 2005

Logging onto most network resources requires the use of a password. Before passwords are sent over networks they are encrypted. Many different variables and algorithms are used to encrypt passwords. The most common method of encrypting passwords before they are sent over a network uses the seconds and minutes fields of file modification time stamps to build variables.

The system doesn’t use the time stamp as a variable directly, but uses them to generate hashes. A hash is a number generated from a string of text. The hash is smaller than the text itself and is generated by a formula in such a way that it is extremely unlikely that some other text would produce the same hash value. Hash values are typically 160 bits in length.

To increase security, hashes are broken up into segments, known as a message digest. These segments are sent over the network in a stream, or the actual data being transferred between two systems. A hash is a one-way function so it will not produce the same message digest from two different inputs. Kerberos uses the date and time stamps of two systems as inputs, which is one reason it is important for systems communicating using Kerberos to keep their clocks in sync. All of this helps ensure the infeasibility of reversing encryption.

Although it is infeasible it is not impossible to break encryption schemes. The NTHash standard of security used by Windows employs a password encryption scheme that simply combines hashes. The NTHash method of password encryption has been exploited. OS X, as with UNIX and Linux, uses a 12-bit string of random numbers to create a more secure hash. This 12-bit string of characters is known as a salt. The use of a 12-bit salt requires brute force attempts to crack encryption will take 4,096 times longer by taking more resources.

Using nonstandard ASCII characters such as !, #, @, *, etc. helps to increase password security as does keeping as up-to-date as possible with security patches. Using Kerberos helps to keep the encryption process as secure as possible due to salted hashes. Another security improvement with Kerberos is that Kerberos creates a ticket upon successful authentication. This ticket is used to access resources across all the servers sharing a common information database such as Open Directory and Active Directory.

In a Kerberos environment passwords don’t have to be sent over the network each time a resource is being accessed. Reducing the frequency of password usage and handling passwords more effectively makes Kerberos a strong weapon in the Network Administrators arsenal. The use of LDAP databases such as Open Directory makes network management easier and more secure.

Network Backbone Glossary

Monday, May 23rd, 2005

Three18 Network Backbone Glossary

Gigabit Ethernet over fibre optic cable
1000Mbps, All four pairs of Cat6 cable utilized at 250Mbps per pair
100 Mbps Ethernet data transmissions over Fibre optic cable
Long wavelength fibre optic transmissions at 100 Mbps.
Short wavelength fibre optic transmissions at 100 Mbps.
100 Mbps Ethernet running over two twisted pairs
Four pairs of Cat3 or better cable. Transmits at 25Mbps on all four pairs.
100 Mbps Ethernet running over twisted pair copper. Full duplex
Thin Ethernet, called thin net or coax
Thick Ethernet cable capable of data transmissions up to 500 meters.
10 Mbps Ethernet running over twisted pair copper cable
Alien Crosstalk
Crosstalk from an adjacent cable or cables
American National Standards Institute.
American Standard Code for Information Interchange. Originally a 7 bit code later 8 bit for communication interfaces
Loss of signal strength and integrity over a given length of cable
The capacity to carry data
The raw data is transmitted using the full bandwidth of the cable with no modulation.
Number of signal or voltage changes per second. Sometimes relates to Bps but not always.
Bayonet connector used with RG58 coaxial cable networks. Thin Ethernet
Bits per second
The bandwidth of the cable is split into multiple modulated channels. Guard bands are used to separate the channels
To send data to more than one device at a time
Bus Network
A network with all devices sharing one common cable.
Category 1, Cat1
Unshielded Twisted Pair for use as speaker or door bell wire.
Category 2, Cat2
UTP for frequencies up to 1.5Mhz. Used in analogue telephone applications.
Category 3, Cat3
UTP for frequencies up to 16Mhz
Category 4, Cat4
UTP 100 ohm for frequencies up to 20Mbs
Category 5, Cat5
UTP 100 ohm for frequencies up to 100Mbs
Category 5E, Cat5E
Enhanced Cat5. Similar to Cat5 with improved specifications
Category 6,Cat6
Proposed cabling standard to support up to 250 Mhz over UTP. Not yet ratified.
Category 7, Cat7
Proposed cabling standard to support up to 600 Mhz over UTP.
Copper Distributed Data Interface as defined by (ANSI X3T12) for 100Mbs token passing over copper twisted pair.
Coaxial cable with a copper screen carrying unbalanced signals
Collision domain
All the nodes on an Ethernet segment that are affected by data collisions. Switches and bridges break up networks into individual collision domains
Centre of a fibre optic cable
interference picked up from an adjacent wire pair within the same cable (see also alien crosstalk)
Carrier Sense Multiple Access with Collision Detect. A NIC transceiver “listens” to the network before transmission and can detect collisions.
Single cable outlet
Drop Cable
The cable from the wall socket to the network device, usually a PC or DTE
Electronics Industry Association in America
Electro Magnetic Interference. Unwanted noise from a source such as fluorescent lighting and electric motors
A LAN protocol and/or cable. Invented by Rank Xerox
Fast Ethernet
Fibre Distributed Data Interface for 100Mbs token passing over Fibre.
Frame Relay
Efficient method of packaging data into frames for transmission over networks
Full duplex
Allows data transmissions in two directions at once. Transmit and receive simultaneously
Gigabit Ethernet
1000Mbps, 1 Billion bits per second over copper cabling
Half Duplex
Single way transmission. Capable of both Transmitting and Receiving but not simultaneously
Institute of Electrical & Electronic Engineers
IEEE 802
The IEEE project number dealing with LAN technologies
IEEE 802.3
Physical cabling layer standards for Ethernet
IEEE 802.5
Physical cabling layer standards for Token Ring
Measurement of the opposition to the flow of electrons in a cable. The combination of Resistance, Capacitance & Inductance.
The collection of communication components that together provide support for the distribution of information within a building or campus
Insertion Loss
The attenuation of a signal as it passes through a connector
A large private company network often spanning many countries
Internet Protocol. Along with TCP is used to track and deliver data packets over a network
Internet Packet Exchange. A Novell networking protocol
Integrated Digital Network Services.
International Standards Organization.
Internet Service Provider. The company who providing a connection to the internet.
A transceiver on an Ethernet network that has failed and is transmitting continuously. May have “locked up” the network with constant storms of packets
Local Area Network
Local Talk
A slow form of LAN linked to AppleTalk network
Media Access Control.
Multiple Access Unit. A token ring hub
The physical wire of fibre for the transmission of signals
Where the single wires in a UTP cable have been attached to the connector in the wrong sequence.
Each wave travelling in an optical fibre.
A device which modulates & demodulates the signals between digital to analogue circuits.
Multi mode
Fibre optic cable thatsupports multiple wavelengths. Can use inexpensive LED light sources.
N Connector
Connectors used for thick Ethernet 10Base-5 cable
Network Interface Card
Numerical Aperture
The angle a fibre cable will gather light and propagate it down the core.
A string of bits containing command information, destination and source addresses and data
Patch Cable
The cable connecting the network panel and the switch or hub
Patch panel
An array of connectors in the network cabinet for plugging in patch cords
Plain Old Telephone System
Premises cabling
The complete cabling infrastructure for the transmission of voice, data and video in a given building.
A data transfer mode using Bit codes, Start Stop bits, Parity. Both transmitter and receiver must use the same protocols.
Public Switched Networks. The telephone system.
A device, usually a network hub or switch that recieves and resends the data boosting the signal
Reversed Pairs
The most common miss wire where the single wires in a pair have been reversed.
Radio Frequency Interference.
Ring Network
Describes a network in a complete ring
Registered Jack number 11. Small line plug and socket used on telephone handsets and modem connections.
Registered Jack number 45. 8 pin plug and socket used on Ethernet cables
Robust but outdated signalling protocol using 2 pairs.
Small Connector used for fibre optic terminations
Small Computer Systems Interface. Connects peripherals to a computer
The area of a network that all node can see each other
Cable with a braided or foil shield to keep out RFI and EMI.
Simple Network Management Protocol. A protocol governing network management and device handling.
Split Pairs
Where the single wires from two different pairs have been swapped. If the same at both ends will not affect short cable transmissions, but will fail over longer distance
ST connector
Straight Tip. A connector for fibre optic terminations
Star network
Network Topology where all devices are attached to a central hub in a star configuration.
Shielded Twisted Pair copper cable
An Ethernet active repeater which reads MAC addresses and routes data to the individual node or network hub. Switches split up networks into smaller individual collision domains. A switch can route data at wire speed through all it’s ports simultaniously.
Transmission Control Protocol. Used with IP to track and deliver packets of data over a network.
An electrical connector attached to the end of a cable to reduce signal reflections and unwanted noise.
Telecommunication Industry Association
Token Ring
A network where a single token is passed around a network between computers. A computer must grab and hold onto the token before it can transmit. After transmission it releases the token back onto the network.
Network architecture, circuit design and transmission protocols
Circuit that transmits and receives data over a network. A NIC contains a transceiver as does a hub and a switch
Twisted Pair
Pairs of 26 AWG wires twisted together the reduce RFI and Crosstalk.
Universal Serial Bus. 12 Mbs connection port
Universal Service Ordering Codes Cabling system original used in the American telephone systems.
Unshielded Twisted Pair. 4 twisted pairs in one sheath.
Wide Area Network