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Quality vs. quantity
Quality vs. quantity
Two of the most miscommunicated concepts in networking are bandwidth and latency. The
quality of your Internet connection is really a composite of both bandwidth and latency,
which is a combination of the size of the pipe plus the time it takes to move data through
For example, your Internet service provider (ISP) might provide you with a 1.5 megabits
per second (Mbps) pipe, which is the size, or bandwidth. You have to measure the speed,
or latency, of the connection. Factors that affect speed include physical factors such as
the electrical properties of the different connecting mediums. For example, the length of
a copper segment might affect latency more than the same length of fiber optic cable
because fiber is less susceptible to signal degradation. Another factor that affects speed is
the number of network devices that a packet needs to pass through when getting from the
source to the destination. This is known as the number of hops between end points. Hops
are increased because of the number of intermediate devices such as gateways, firewalls,
and routers. You can increase your bandwidth by purchasing more or by combining
multiple pipes. It is more difficult to reduce latency because you might not have control over
the connection medium, but you might have control in reducing the number of
intermediate devices or making those devices more efficient by upgrading the network cards in the
devices. You also might be able to work with your ISP to reduce the number of hops or use
a different ISP that might be closer to the Internet backbone or is part of the Internet
backbone. We will discuss the importance of the Internet backbone in the “Misconception about
distance” section later in this chapter.
To measure the quality of your network connection, you need to fully measure the
throughput in terms of bits per second (bps), Mbps, and gigabits per second (Gbps).
A popular network topology is a star topology where the Internet connection might be
located at the corporate headquarters or some central location. Branch offices might
need to traverse point-to-point network connections such as fiber, T1/DS3, frame relay,
microwave, or other types of leased lines to get to the corporate Internet gateways.
We have seen many customers focus only on their Internet connection and overlook
these point-to-point connections between branch offices. Office 365 is designed to
be a secure solution so all transmissions are encrypted through a Secure Sockets Layer
(SSL) or Transport Layer Security (TLS). This adds overhead. Furthermore, if you employ
network acceleration technologies, these might no longer work in Office 365 because
many network acceleration technologies need to have the ability to look inside the
packets in order to apply compression algorithms. Encrypted packets prevent the
ability to look inside packets, thus rendering network acceleration technologies ineffective.
These are examples of impacts to the corporate network that you need to pay attention
to, especially if you have multiple branch or remote offices.