Campus Network Overview Carl Harris Associate Director, Research and Development Communications...
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Transcript of Campus Network Overview Carl Harris Associate Director, Research and Development Communications...
Campus Network Overview
Carl Harris
Associate Director, Research and Development
Communications Network Services
Virginia Tech
What is CNS?
• Communications Network Services provides the following services to Virginia Tech faculty, staff, and students– traditional telephone and voice-mail
– cable television (mostly residence halls)
– IP/IPX/AppleTalk network layer and below• Exception: DNS and DHCP
• Provide services on Blacksburg campus and at graduate centers around the state.
Basic Link Layer Services
• Basic Ethernet portal service– Switched 10Base-T (10 Mbit/s)
– Some switched 100Base-TX (100 Mbit/s), but very expensive.
• Dial-in modem pool with ~1,200 56K modems.• MSAP provides campus backbone access to local
ISPs.– Ethernet in apartment complexes
• ATM portal service for specialized applications (e.g. videoconferencing used in distance learning programs)
Network Layer Architecture
• IP routing– Within our autonomous system (AS):
• OSPF plus some static routes
– Extending beyond our (AS): • BGP4+ (a.k.a. MBGP) plus some static routes
• In the modem pool:EIGRP (Cisco proprietary): fast convergence, low overhead, few knobs. Low CPU cost despite lots of link state changes.
– Coming soon:• Multiprotocol Label Switching (MPLS, a.k.a. tag switching) to
support certain kinds of policy routing
• Packet prioritization and custom queuing disciplines to support apps with strict latency and loss requirements.
Network Layer Architecture
• IP multicast routing– Within our AS:
• Protocol Independent Multicast, Sparse Mode (PIM-SM) between routers.
• Internet Group Management Protocol (IGMPv2) manages multicast group membership to control distribution to hosts.
– Extending beyond our AS:• PIM-SM
• MBGP (multiprotocol, not multicast)
• Multicast Source Discovery Protocol (MSDP)
• A few legacy DVMRP tunnels
Network Layer Architecture
• IPX routing: IPX RIP, NLSP (similar to OSPF)• AppleTalk routing: who cares?
Layer 1 and 2 Architecture
• Primary switching facilities are located in:– Andrews Information Systems Building
– Cassell Coliseum
– Burruss Hall
– Hillcrest Hall
– Owens Hall
– Shanks Hall
• Use fiber-optics to interconnect switching facilities and to fan out to building backbones.
Layer 1 and 2 Architecture
• ATM backbone used as a “substrate” on which to build network layer services.– LAN Emulation (LANE)
• Routers connect to ATM backbone and use LANE to establish virtual connections to each building subnet. LANE also used to interconnect the routers to form a network layer backbone.
• Ethernet switches with LANE capability used in building backbones, ATM connection to campus backbone.
10
0B
ase
-FX
do
wn
links
CiscoCatalyst
5000
Catalyst 1924
Catalyst 1924
Catalyst 1924
Catalyst 1924
Catalyst 1924
MDF
ATM OC3cFORE
ASX-1000Cisco 7507
• Ethernet edge switches go in wiring closets located throughout the building
• LANE connects the router (Cisco 7507) to the primary building switch (Catalyst 5000) via the ATM backbone switch.
Type III Building Network
10Base-Tto wall portal
MSAP
xDSL
T1/FR
LMDS
ModemPool
N.W.V
VT ATM Backbone (since 1996)
OC3c ATM (155 Mbit/s)
OC12c ATM (622 Mbit/s)
SHAFORE
ASX-1000
OWEFORE
ASX-1000
HILFORE
ASX-1000
ISBCisco 7507
Internet
Internet2
ISBFORE
ASX-1000
BURFORE
ASX-1000
CASFORE
ASX-1000
ISBCisco 7507
CASCisco 7507
OWECisco 7507
SHACisco 7507
BURCisco 7507
HILCisco 7507
ISBCisco 7507
ISBCatalyst
5500
HILCatalyst
5000
BURCatalyst
5500
SHACatalyst
5500
OWECatalyst
5000
CASCatalyst
5000
What Now?
• Need low cost 10/100Base-TX portal service• Need to provide greater resiliency, lower latency,
more bandwidth, and packet switching with differentiated QoS for next-generation applications– university administrators using desktop
videoconferencing over IP
– telephone services (voice-over-IP)
– bandwidth killer applications (e.g. Napster)
• Need architecture consist with high-bit-rate multicast (e.g. streaming HDTV via multicast).
• 2 x 100Base-FX building feed, no more ATM
• Simpler model.
• Low cost conversion
• Scalable building feed
CiscoCatalyst
5000
Type IV Building Network
CiscoCatalyst
6509
Catalyst 1924
Catalyst 1924
Catalyst 1924
Catalyst 1924
Catalyst 1924
MDF
2 x 100Base-FX
10
0B
ase
-FX
do
wn
links
10Base-Tto wall portal
• 10/100 to the desktop
• High capacity building
concentrator switch.• Scalable Gigabit Ethernet building
backbone.
• Deployed in ACITC
Type V Building Network
CiscoCatalyst
6509
Catalyst 3524
Catalyst 3524
Catalyst 3524
Catalyst 3524
Catalyst 3524
Catalyst 3524
Catalyst 3524
Catalyst 3524
CiscoCatalyst
6509
MDF
2 x 1000Base-LX
10
00
Ba
se-S
X d
ow
nli n
ks
1000Base-T4 interswitch links
10/100Base-TXto wall portal
MSAP
xDSL
T1/FR
LMDS
ModemPool
VT ATM
Backbone
N.W.V
VT Gigabit Backbone (Fall 2000)
1 x 1000Base-SX
1 x 1000Base-LX
2 x 1000Base-LX
ATM OC3c
1 x 100Base-FX/TX SHACatalyst
6509
OWECatalyst
6509
HILCatalyst
6509
ISBCisco 7507
Internet
Internet2
ISBCatalyst
6509
BURCatalyst
6509
CASCatalyst
6509
ISBCatalyst
6006
ISBCisco 7507
CASCisco 7507
Future POS/DPT/ATM OC12cor 1000Base-ZX
VT ATM Backbone (Fall 2000)
N.W.VVT
GigabitBackbone
ATM OC3c multi-mode
ATM OC3c single-mode
1000Base-SX
Internet
Internet2
SHAASX-200WG
OWEASX-200WG
BURASX-200BX
CASASX-200BX
ISBASX-1000
HILASX-200BX
CASCisco 7507
ISBCisco 7507
ISBCisco 7507
Net.Work.Virginia
• Provides ATM services throughout Virginia to K-12 schools, institutions of higher education, and state agencies– low cost access with level pricing statewide
• OC3c (155 Mbit/s), ~ $150,000/annum
• DS3 (45 Mbit/s), ~$60,000/annum
• DS1 (1.5 Mbit/s), ~12,000/annum
– provides Internet access services, as well as supporting a wealth of ATM-based services (intranet, videoconferening, PSTN toll bypass, etc).
– provides access to Internet2 backbones (Abilene, vBNS)
For More Information
• rdweb.cns.vt.edu• www.networkvirginia.net• www.internet2.edu• www.abilene.iu.edu