The campus network and its connections within New Hampshire
and to the world are designed and managed by the Telecom
part of Computing & Information Services. See their
Network Operations Center,
or NOC, for links to traffic graphs and other
information.
-
Cabling.
The UNH network backbone for our Intranet
or LANS consists of fiber optic
cable running between the major buildings on campus.
Within each building the preferred wiring is category 5,
twisted-pair copper wires (some older wiring does not
meet that standard).
-
Subnets.
The IP network is organized into subnets to control
routing of traffic (packets), i.e., to localize as
much traffic as possible rather than broadcast it over
the whole campus network. These physical subnets are referred
to by various colors such as black, blue, orange, slate,
etc. Specific IP address ranges are assigned to each
subnet (see table below).
-
LAN protocols.
ATM and Ethernet are used as the underlying transport
"vehicle" (i.e., the standard as implemented in
hardware and software) by the upper-level protocols.
ATM (asynchronous transfer mode) is new on campus
and will be used instead of Ethernet for the higher
speed links in the backbone. An advantage of ATM
is that it allows for "virtual circuits," the ability
to dedicate part of the bandwidth to support
better quality
video and audio applications (no dropouts). See the
ATM tutorials
for more information on the basic technology.
If we think in terms of the four-layer TCP/IP protocol
stack that consists of the link, network,
transport, and application layers (in contrast
to the seven-layer ISO protocol stack), then
the predominant LAN protocol is IP (network layer), mostly at
10 Mbps, but with some links upgraded to 100 Mbps.
Other LAN protocols are also in use and run over part
or all of the
same cabling/wires. These include IPX (Novell),
Appletalk (Apple),
and DECNET (Digital Equipment). Their
importance is declining as vendors put less emphasis
on their proprietary protocols and more on TCP/IP.
-
Bandwidth.
Bandwidth is the capacity of a network
link or connection, measured in bits per second
("bps" or "bits/sec").
At common modem speeds we talk about 28800 bps ("28.8")
and 56000 bps ("56K").
The theoretical bandwidth of much of our Ethernet
on campus is 10 megabits per second(Mbps), though the
achievable maximum use is much less than that.
There are several standard size links (or "pipes"
as network-techs like to call them, even though
they are actually tiny strands of fiber optic
cable) in use for the Internet. Most of these are
measured in megabits per second, but the technology
is racing toward gigabits (billions of bits) per
second as an operational goal.
...............................................
service carrier bit rate
name line name
...............................................
DS1 T1 1.5 Mbps
DS3 T3 44.7 Mbps
STS-1 OC3 155.5 Mbps
STS-12 OC12 622.0 Mbps
...............................................
-
Internet connection.
Our current UNH access provider to the Internet is
Frontier Communications.
USNH has an OC3 connection to the Internet.
See the
map showing connectivity in the State.
UNH is a member of the
Internet2 consortium and funding is in hand
and planning is underway for a T3 connection to
the Internet to support that membership.
That introduces a new layer of terminology, such
as NGI, vBNS, and GigaPoP.
NGI (Next Generation Internet)
is "complementary and interdependent" with the
Internet2 collaboration. If you think in terms
of Venn diagrams, organizations with NGI projects
overlap with the university-dominated Internet2, but
are not the same. Similarly, some of the Internet2
schools are part of the vBNS (very high performance
Backbone Network Service), but not all are. The
GigaPoPs (Gigabit per second Points of Presence)
are to provide highspeed regional connectivity of
universities and other organizations.
-
Domain.
UNH is registered as a Class B Internet domain. That
gives us a block of 65,000+ addresses
(2^16) to manage. The IP
prefix for our domain is "132.177". All our domain names
end in "unh.edu". The domain name for Plymouth State
College is "plymouth.edu" and for Keene State College it
is "keene.edu".
-
Domain name administrator.
Our block of addresses is called our "address space"
and it is up to us to manage it according to the protocols
and procedures established for the Internet. That means
we have a "domain name administrator" who registers
addresses for any UNH system, maintains a database. That
person is in the Telecommunications part of
Computing and Information Services, and is reachable via
e-mail at
ip-request@unh.edu.
-
Host names.
All systems that connect to the campus network
require a numeric address and a corresponding
network name. These assignments can be either
static (fixed over time) or dynamic (issued from
a pool of addresses and names, but varying from
session to session). For more on dynamic
assignment, see the DHCP section below.
If a system is eligible for a static adddress,
you can choose almost any name you want,
if it is not already in use
and is not obviously offensive. The name is prefixed to
the "unh.edu" domain, so if you chose the name "foobar"
the domain name for the computer would be "foobar.unh.edu".
The actual IP number is assigned by the domain name
administrator. Groups with multiple systems to register
often adopt (and may require) a convention for
generating names, ranging
from the simple (such as mac-01, mac-02, etc.) to the
exotic (such as rivers in the Amazon Basin).
-
Central Unix Systems.
We refer to our general-purpose central Unix
systems collectively as "CISUNIX".
Two of our central Unix computers are named for
prominent women. "Christa" is named for
Christa McAuliffe,
the NH teacher and astronaut who died in the Challenger
explosion.
"Hopper" is named for
Grace Murray Hopper, the Navy admiral
who was involved with computers in the early days of
the 1950's and who in later life was a spokesperson for the
Navy. She often demonstrated a nanosecond (a billionth of
a second) by handing out pieces of wire about 12 inches
long, since that is the distance light would travel in a
nanosecond in a vacuum.
-
IP addresses.
Internet addresses are 32 bits. Our Class B address
space means that we have 16 address bits to work with
(i.e., 2^16=65,000+). To help manage this address
space effectively it is divided into subnets. A common
scheme on the Internet is to divide the 16 bits so that
8 bits are used for subnets (256 subnets) and 8 bits are
used for systems on each subnet (up to 256 systems on a
subnet). This corresponds to a "subnet mask" of
"255.255.255.0". The plan implemented for UNH is
based on the assumption that we were more likely
to need fewer subnets but to want more systems on a given
subnet, so our address space is partioned to have 6 bits
for subnets (up to 64) and 10 bits for systems on a subnet
(up to 1024).
BTW, I'm simplifying slightly here, since one or
two of the addresses in each subnet is normally not
available for assignment. More than 4000 addresses in
our address space are already assigned.
-
Gateways and masks.
When you receive your address from the
domain administrator it includes the address for your
subnet gateway and the subnet mask. This table
summarizes the subnet information (contributed by
Scott Kitterman and Mike Maddix):
......................................................
subnet name gateway subnet mask
......................................................
black.unh.edu 132.177.136.1 255.255.252.0
blue.unh.edu 132.177.148.1 255.255.252.0
brown.unh.edu 132.177.160.1 255.255.252.0
gold.unh.edu 132.177.40.1 255.255.252.0
orange.unh.edu 132.177.152.1 255.255.252.0
red.unh.edu 132.177.132.1 255.255.252.0
silver.unh.edu 132.177.44.1 255.255.252.0
slate.unh.edu 132.177.164.1 255.255.252.0
violet.unh.edu 132.177.144.1 255.255.252.0
white.unh.edu 132.177.129.155 255.255.252.0
yellow.unh.edu 132.177.140.1 255.255.252.0
......................................................
-
Subnet delegation.
Responsibility for a subnet can be delegated and
UNH has several examples of that, such as "cs.unh.edu"
managed by the
Computer Science Department,
"sr.unh.edu" for that sponsored research activity
managed by the
Research Computing Center,
and "iol.unh.edu" managed by the
InterOperability Lab.
-
Domain name servers.
We have one primary domain name server where the master
copy of the database is kept and then propagated to secondary
servers. The ability for your TCP/IP software to look up
addresses in the domain name database is so critical that
this redundancy is important. It also allows us to distribute
the load on the database across multiple systems.
..................................................
server type name IP address
..................................................
primary nic.unh.edu 132.177.128.99
secondary unhsst.unh.edu 132.177.128.56
secondary unhbound.unh.edu 132.177.152.9
secondary ns1.unh.edu 132.177.100.31
secondary ns2.unh.edu 132.177.1101.32
..................................................
-
Dynamic Host Configuration Protocol (DHCP).
DHCP was developed to make it practical to administer
growing networks of desktop TCP/IP systems. The desktop
system receives the network information it needs from
the DHCP server, including a dynamically assigned IP
address (leased). For systems that need to retain
the same address over time (servers, desktops granted
access to information on the basis of their IP address,
etc.), DHCP allows reservations (unlimited leases) of
a static address. UNH is starting to implement DHCP.
A variety of DHCP
RFCs and FAQ material is on the Web.
-
Nslookup command.
An important tool for looking up domain information
is "nslookup". You can use it either to make queries
about single IP addresses, single domain names, or
whole sites. On our central Unix systems you can get
more information at the shell prompt by:
% man nslookup
or you can use this URL:
http://pubpages.unh.edu/cgi-bin/man-cgi?nslookup
and on our central VMS systems you can ask for:
$ HELP MULTINET NSLOOKUP
-
PPP or SLIP access.
For people who want a SLIP or PPP connection
to the campus network, we direct them to get
connected via an Internet Service Provider (ISP), with
Ultranet as the recommended provider for those located
in much of New Hampshire (there is a 15% rate discount
negotiated for USNH faculty, staff, students).
University System of New Hampshire
Wide Area Network (USNH WAN).
contributed by Doug Green.
dgreen@cisunix.unh.edu
The
USNH
WAN includes T1 connections from the UNH Durham
LAN to
Keene State College, Plymouth State College, UNH Manchester, and The
Dunlap/Meyers administrative center in Lee. We have leased 56 kbps (DDS2)
connections to the
College for Lifelong Learning (CLL)
sites in Concord and
Manchester, to the Jackson Marine Lab on Great Bay, and to the
Oyster River High School.
The USNH WAN also includes a Frame Relay network
connecting
Cooperative Extension System (CES) sites from UNH Durham to
Conway, Boscawen, Keene, and Dover. All other CLL and CES sites currently
connect to Durham using a relatively slow 1-(800) dial X.25 service from
Nynex known as Infopath.
Check out
a map.
Modem dial service is available at discounted rates to all
students, faculty, and staff through Ultranet, a commercial Internet
Service Provider (ISP). Ultranet has a modem bank and router on the UNH
campus. Ultranet provides Internet connectivity to that router via a T1
connection to their local Point of Presence (POP) in Portsmouth.
Additionally, the UNH LAN is directly connected to the Ultranet router.
This provides direct, high-speed UNH LAN access to all dial users.
Current plans include expansion of the CES Frame Relay network to
connect Laconia, Lancaster, Brentwood, Goffstown, Milford, Newport, and N.
Haverhill covering all the NH counties. These will be deployed
incrementally over the 97/98 school year.
We are also expanding the CLL
directly-connected network to
include Lebanon, Portsmouth, and Claremont over the 97/98 school year. We
will be converting the CLL network from DDS connections to a combination
of Frame Relay and a hybrid data system. The hybrid data system utilizes
spare bandwidth on the Interactive Television (ITV) T1 network. This will
consolidate some USNH network services simplifying management and reducing
leased line and maintenance costs.
