Transcript Business Data Communications

Business Data Communications
Chapter Nine
Enterprise Solutions
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Primary Learning Objectives
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Describe direct attached storage
Define a storage area network
Explain network attached storage
Understand virtual private networking
Define Voice-over-IP
Identify two key elements of Web services
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Economics of Data and Information
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Direct Attached Storage –
DAS
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Is a mature storage technology that has been
available for several decades
Is usually associated with magnetic tape and hard
drives
For servers, is usually implemented using SCSI:
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SCSI is a block-level I/O protocol
SCSI commands can be issued over Ethernet, Fibre
Channel, Serial Storage Architecture, or over standard
SCSI parallel cables
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SCSI cables have a 25-meter length limitation
Most SCSI DAS implementations use standard SCSI cables
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Direct Attached Storage –
DAS
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A DAS server:
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Does not support capacity sharing, which allows a storage
device to pool storage space with other processors
Capacity sharing:
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Provides for scalability
Allows a pool of storage space to be defined from multiple
devices
Is associated with multiple servers
Does not support data sharing, which is the capability of a
storage device to share data and files with other storage
devices
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Data sharing is associated with a single server
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Direct Attached Storage –
DAS
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Storage Area Network –
SAN
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Is itself a network
Is composed of storage devices that other
computers--servers or clients--can access
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Storage of commonly used resources are removed from
the LAN and placed instead on the SAN
Generally uses servers to provide the interface
between itself and LAN clients
Is often implemented using Fibre Channel
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SAN
Clients, through the
LAN, access servers
that, in turn, through
the SAN, access
storage devices, on
the clients’ behalf.
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Storage Area Network –
SAN
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Optimized for storage traffic, a SAN:
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Is capable of managing multiple hard and tape drives as a single
pool
Provides a single point of control
Offers specialized backup facilities that reduce server and LAN
utilization
Allows for greater distances between clients and servers that
access data, and the storage devices where the data is housed
Usually results in virtualization of the SAN for the clients that
utilize it
Requires a management component
Can be costly to implement, but has significant advantages
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Storage Area Network –
Relevant SAN Questions
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Which applications in use would justify the SAN?
How are current storage and server capacities
being utilized?
How many departments and/or locations could
benefit from a SAN?
What business objectives would a SAN address?
What technical staffing is available to manage the
SAN?
How have past server and storage technologies
been budgeted?
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Network Attached Storage –
NAS
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Can be implemented in conjunction with a SAN or
as a stand-alone solution
Devices are also called NAS appliances
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These devices provide high-performance data and file
sharing to clients and servers in a LAN
Applications include:
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Data mining
Knowledge management
Data warehousing
Trend analysis
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Network Attached Storage –
NAS
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NAS devices:
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Have an internal, integrated processor
Typically use either a hub or switch to connect to a LAN or
WAN
Must be attached to a network that supports IP-based
protocols
Use a stripped-down and proprietary operating system
Use specialized file sharing protocols, such as:
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Network File System (NFS)
Common Internet File System (CIFS)
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Network Attached Storage –
NAS
In this configuration
the NAS appliances
are attached to a
TCP/IP LAN and are
accessed by using
specialized file
access and sharing
protocols.
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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NAS
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Network Attached Storage –
NAS
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Can be directly connected to the LAN or WAN
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Can be placed on a separate dedicated storage
network
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Useful when storing frequently used individual client files
Useful when storing a resource, such as a database,
needed by many clients and/or networks
Can run on lower-cost Ethernet networks
Is relatively easy to install
Permits resource pooling only within the device
itself
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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DAS vs SAN vs NAS
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Virtual Private Networking –
VPN
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Is a private network that utilizes a common carrier’s
telecommunications infrastructure
Implements privacy using various tunneling and
security procedures
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Tunneling is a technique that allows packets from one
protocol to be wrapped within a second protocol
In effect, results in businesses’ outsourcing their
networking infrastructure
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Virtual Private Networking –
VPN
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Permits many businesses to concurrently utilize a
common carrier’s telecommunications infrastructure
for their VPN
Provides many of the benefits of private leased
lines, but at a reduced cost
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However, a business has no control over the common
carrier’s infrastructure
Is implemented in one of three ways:
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Trusted – the oldest
Secure
Hybrid – the newest
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Trusted VPNs
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Require that the business “trust” the common
carrier to provide secure and reliable services
Depend on only the carrier to affect the creation or
modification of the VPN’s path:
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The path is the series of links between sender and receiver
Many customers use the same links within a path
To be established, VPNs must define routing and
addressing between sender and receiver
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Trusted VPNs
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Secure VPNs
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Encrypt the data at the sender’s end
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Unencrypt the data at the receiver's end
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Encryption scrambles the data so that unauthorized users
are not able to interpret it
The sender and receiver must share the same encryption
technology and key
Require that all parties in the secure VPN agree to
the encryption and security methods implemented
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Encryption does require a time element
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Secure VPNs
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Establish two endpoints, the sender’s and the
receiver’s
Require administrators from each endpoint to agree
on the characteristics of the secure VPN tunnel
Must not permit someone outside the secure VPN
to affect the security properties of the VPN
Require more processes, or steps, than a simple
trusted VPN
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Secure VPNs
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Hybrid VPNs
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Enable one portion of a communication to be
trusted and another to be secure
Allow the secure part of the hybrid VPN to be
controlled by the customer or the common carrier
provider
Must have well-defined boundaries between the
trusted and secure VPN
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Network administrators on each end of the connection
must be able to determine which portion of a
communication uses encryption and which does not
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Virtual Private Networking –
VPN
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Most frequently has these uses:
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Secure remote access
Intranet access
Extranet access
Is particularly associated with Internet Protocol
Security, standardized by the IETF
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Some other protocols used with VPNs are:
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Point-to-Point Tunneling
Multi-Protocol Label Switching
Layer-2 Tunneling
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Voice-over-IP –
VoIP
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Is a data service promising to provide many
standard voice functionalities, including:
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Supervision
Signaling
Dialing
Voice transmission
Call routing
Ring
Billing
Administration
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Voice-over-IP –
Standard Voice vs. VoIP
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Standard voice communications are carried as
direct current on copper wire
VoIP uses a bit stream on copper wire
Standard voice is analog
VoIP is digital
Standard voice transmission is continuous
VoIP is packetized
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Voice-over-IP –
VoIP
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VoIP potentially results in significant cost savings:
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Creates a single infrastructure for voice and data
Virtualizes telephone operations
Supports unified messaging
Allows for linkage of customer resource management
(CRM) applications with computer-telephone integration
Possible VoIP implementation questions:
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What is current network utilization?
Are network elements in place that support VoIP?
Does the current network support IP-based QoS?
What are current and future voice bandwidth
requirements?
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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VoIP
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Web Services
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An umbrella term referring to a suite of software
components designed to dynamically interact with
each other using Internet standards
Three standard-setting organizations particularly
associated with Web services are:
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World Wide Web Consortium (W3C)
Organization for the Advancement of Structured
Information Standards (OASIS)
Distributed Management Task Force (DMTF)
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Web Services
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Web Services
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Utilize two key elements:
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Languages and protocols that allow devices, software, and
people to better communicate and collaborate
A key Web services language is XML, Extensible Markup
Language
A key Web services protocol is SOAP, Simple Object Access
Protocol
Web services are device and operating system
platform-independent
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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Web Services
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Steps in a Simplified
SOAP Request/Response
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In Summary
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DAS is a mature storage solution
Newer storage solutions include SAN and NAS
A SAN and a NAS can be configured jointly or
independently
A SAN typically uses Fibre Channel, and a NAS SCSI
VPNs allow a business to create a network, using
common carrier infrastructures
VoIP can implement a single infrastructure for voice
and data
Web services utilize languages and protocols that
are platform-independent
Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall
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