ASSIGNMENT NO:

Aim:Backbone network design-A college case study

Theory:

What is backbone?

A backbone is a larger transmission line that carries data gathered from smaller lines that interconnect with it. It is a portion of a computer network that is capable of carrying the majority of traffic on the network at high speeds.

At a local level, a backbone is a line or set of lines that local area networks connect to for a wide area of network connection or within a local area network to span distances efficiently (for e.g. between buildings). On the internet or other WAN, a backbone is a set of paths that local or regional networks connect to for long distance interconnection.

A backbone is a means of connecting two or more LANs. Within the structured cabling environment the term backbone refers to the cable used to connect a main or intermediate cross-connect to a telecommunication closet .The term backbone refers to a physical portion of the structured cabling system.

The first internet backbone was made between UCLA and SLI in 1969 and today the internet consists of dozens of large backbone that carry the majority of traffic throughout the world.

Types or Architecture of backbone networks

There are four basic types of backbone networks

1. Hierarchical network

In this type of network, each LAN is a separate and isolated network, connected by a TCP/IP gateway (usually a router) to a shared media backbone network. Within the LAN, messages are sent based on the data link layer addresses. To move between LANs,message traffic needs to be sent specifically to the router,which forwards the message based on its network layer address.

This network must be able to simultaneously serve all attached LAN’s. The traffic circulating on each individual LAN must be kept separate from the backbone network traffic through the use of backbone access devices such as routers.

Hierarchical Backbone Network

2. Flat Backbone Network

In this type of network,LANs are connected using bridges or layer-2 switches.Packets are forwardedbased on their data link layer addresses, making the entire flat backbone a single subnet.

Flat backbones using bridges were developed in the mid-1980s to reduce costs, because at that time routers were very expensive. Bridges are now replaced by layer-2 switches.

Flat Backbone Network

3. Collapsed Backbone Network

A Collapsed backbone network is one where individual physical networks are connected in a star fashion to a central device.This device centralizes backbone network services.

Collapsed backbones use either layer-2 switches or layer-3 routing switches. It is of two types:-

a) Rack Mounted

It collapses the backbone into a single room,called a main distribution facility(MDF) where networking equipment is connected and mounted on equipment racks.Devices are connected using short path cables.

Rack mounted Collapsed backbone network

b) Chassis Based

Chassis switch designs include a number of open clots and have an internal capability capable of supporting all active modules.

Collapsed backbone network

4. Virtual LANs

VLANs are a new type of LAN architecture using intelligent, high-speed switches. VLANs assign computers to LAN segments by software.It has two basic designs

a) Single Switch VLANs

Computers are assigned to VLANs using special software,but physically connected together using a large physical switch

Single switch VLANs

b) Multi-switch VLANs

Multi-switch VLANs send packets between multiple switches,making VLANs with segments in separate locations possible.

Multi-switch VLANs

VLAN

Current Backbone technologies

The current backbone technology used is collapsed backbone or VLANs

Advantages of Collapsed backbone

1. Each connection to the switch becomes a separate point-to-point circuit also giving much higher performance (from 200-600% higher).

2. The network has far fewer devices and so is much simpler to manage.

Disadvantages of Collapsed Backbone

1. Use more cable and the cable runs for longer distances.2. If the central switch fails, the network goes down.

ATM is also used.

Advantages of ATM

1. Provide end-to-end quality of service2. High bandwidth3. Scalable4. Manageable5. Cost-effective6. Fixed-size packets (cells)

7. Small packet size8. Statistical multiplexing9. Integrated services

Disadvantages of ATM

1. Quality of service is defined, but not used2. Competition from other LAN technologies like Fast Ethernet, FDDI etc.3. Standardization of ATM is slow.4. Due to fixed and small packet size,overhead for sending small amounts of data is

there. Also there is segmentation and reassembly cost.

Gigabit Ethernet use is growing. It can have a range of about 5 miles. ATM, while still popular in WANs, is losing ground to Gigabit Ethernet as a backbone technology.Taken together, it appears that Ethernet use dominates both the LAN and backbone environments.

Typical Characteristics to be looked at while deciding typical backbone design of network

The typical characteristics are:

1. Topology

Topology describes the physical appearance of the network. Commonly used topology is collapsed backbone.

2. Transmission Technique

It is based on network technology being used. While many technologies may be employed, a few of them include Ethernet, Token-ring, FDDI, ATM etc.

3. Speed

The speed at which backbone network operates is a function of the technology being employed .It must be considered that backbone networks are often designed to meet greater traffic requirements over long distances than individual LAN environments. Thus, the technologies employed on the backbone network often use high speed networking.

4. Scalability and Extensibility

The backbone network should be chosen such that it is scalable and extensible. Collapsed backbone technology is extensible due to star topology.

Giga Ethernet Implementation

Topology

College backbone network is composed of a 52.5 micron, 4 core multimode fiber optic cable. It connects all the floors. It terminates at main switches having fiber ports. Active components of the backbone are D Link/CISCO switches. Cable media used are provided by AVAYA (Systimax).The data rate for the backbone network is 1000 Mbps. We use GBIC for stacking purpose.Duplex SC Connectors are used.

Duplex SC connector

Horizontal Cabling

1. A SCST cable connects the LRJ to the switch rack on the 3 rd floor which houses several 24 port switches. A duplex SCST connector is used for this purpose.

2. The switch rack contains any switches (DLINK DES3226S). This is a regular 24 port switch with 10/100 ports.

3. There is a jack panel switch per switches. The use of jack panel ensures ease of fault isolation and maintenance. This is because jack panel is a passive device and hence is easier to test in case of some problems of breakdowns.

4. The horizontal cabling is done on each floor using CAT 5/CAT6 cables which end in the switch rack.

Vertical Cabling

1. The vertical cabling is done using fiber optic cable that runs vertically from one floor to other using LIUs.

2. To ensure privacy of data within the college, two devices are used, the cisco ASA 5510 and ALLOT fiber optic cable runs from the ISP to cisco ASA(Advances security appliance) 5510 firewall.

3. All departments within the college are connected to a CISCO Layer 3 switch which is on the 3rd floor via LIU.

4. Switch rack on 3rd floor also lowers ALLOT Bandwidth tool as well as well as the firewall which in turn is connected to ISPs.

Details about various Network components

1. Backbone Switch- CISCO L3 Switch 3750

Cisco 3750 Switches

The CiscoCatalyst3750 Series is an innovative line of multilayer Fast Ethernet and Gigabit Ethernet switches featuring Cisco Stack Wise™ technology that allows customers to build a unified, highly resilient switching system—one switch at a time.

Key Features

Stackable, fixed-configuration switches with Cisco Stack Wise™ technology and a 32-Gbps interconnect for a unified, resilient system of up to nine switches

Layer 2-4 switching and intelligent services with dynamic IP routing and IPv6 Fast Ethernet, Gigabit Ethernet, and 10 Gigabit Ethernet connectivity Up to 48 10/100/1000 ports plus 4 Small Form-Factor Pluggable (SFP) ports per

stackable switch Integrated Power over Ethernet (PoE) (Cisco pre-standard and IEEE 802.3af); up to

24 ports with 15.4 watts (W) or 48 ports with 7.3W Integrated wireless LAN controller supporting up to 200 access points AC power supply failure protection with external redundant power supply

Key Benefits Availability—802.1S/W enables standards-based fault tolerance, load balancing, and

rapid recovery Cisco Stack Wise™ Technology—One IP address and one command-line interface

(CLI) simplify management; a 32-Gbps resilient -architecture speeds convergence Power over Ethernet (PoE)—370W PoE simplify IP telephony, wireless, and video

surveillance deployments; intelligent powermanagement features provide greater control and help extend the power budget; combined with Fast Ethernet or Gigabit Ethernet maximizes existing infrastructure investment

Layer 3—Advanced routing protocols like Open Shortest Path First (OSPF),Enhanced Interior Gateway Routing Protocol (EIGRP), Border Gateway Protocol (BGP), Static Routing, and Policy Based Routing (PBR) increase network scale; equal-cost routing as well as multicast routing such as Protocol Independent Multicast (PIM) maximize network resources; Virtual Route Forwarding Lite (VRF-Lite) secures traffic; IPv6 simplifies network addressing and mobile IP while increasing security

QoS—Traffic Shaping smoothes bursty traffic flows without dropping packets; shaped Round Robin helps guarantee bandwidth to mission-critical applications; Scavenger Queuing protects against worms that can overload resources

Management—Cisco Smartports allows fast and easy configuration of advanced Cisco Catalyst intelligent features; express setup facilitates quick and easy setup through a Web-based interface; resource templates help tailor switch resources for the application

Security—Dynamic Host Configuration Protocol (DHCP) snooping allows only trusted ports to relay DHCP messages, eliminating rogue DHCP servers; Network Access Control (NAC) prevents the propagation of costly worms and viruses; Dynamic ARP Inspection and IP Source Guard prevent against man-in-the-middle attacks; 802.1x and Identity-Based Network Services allow only authorized persons on the network; port security prevents MAC address flooding attacks

Wireless—Integrated wireless LAN controller delivers centralized security policies, intrusion protection, RF management, QoS and Layer 3 fast secure roaming for Wireless LANs (WLANs)

2. CISCO ASA 5510

The Cisco ASA 5510 Adaptive Security Appliance delivers advanced security and networking services for small and medium-sized businesses and enterprise remote/branch offices in an easy-to-deploy, cost-effective appliance. These services can be easily managed and monitored by the integrated Cisco ASDM application, thus reducing the overall deployment and operations costs associated with providing this high level of security. The Cisco ASA 5510 Adaptive Security Appliance provides high-performance firewall and VPN services and five integrated 10/100 Fast Ethernet interfaces. It optionally provides high-performance intrusion prevention and worm mitigation services through the AIP SSM, or comprehensive malware protection services through the CSC SSM. This unique combination of services on a single platform makes the Cisco ASA 5510 an excellent choice for businesses requiring a cost-effective, extensible, DMZ-enabled security solution.

As business needs grow, customers can install a Security Plus license, upgrading two of the Cisco ASA 5510 Adaptive Security Appliance interfaces to Gigabit Ethernet and enabling integration into switched network environments through VLAN support. This upgrade license maximizes business continuity by enabling Active/Active and Active/Standby high-availability services. Using the optional security context capabilities of the Cisco ASA 5510 Adaptive Security Appliance, businesses can deploy up to five virtual firewalls within an appliance to enable compartmentalized control of security policies on a departmental level. This virtualization strengthens security and reduces overall management and support costs while consolidating multiple security devices into a single appliance.

3. GBIC

GBIC Module Slot LED Location on a Switch

GBIC LED Location on a 1000BASE-X Module

The Cisco Systems GigaStack® Gigabit Interface Converter (GBIC) is a versatile, low-cost, Gigabit Ethernet stacking GBIC that offers high-speed interconnectivity between Catalyst® 3550, 2950G, 3500 XL and modular Catalyst 2900 XL Switches.

The GigaStack GBIC is implemented in a standard GBIC form, which offers customers the highest level of deployment flexibility and scalability. TheGigaStack GBIC offers wiring closet deployment flexibility through its dual operating modes. It delivers a 1-Gbps forwarding rate in a half-duplex cascade configuration or up to 2-Gbps full-duplex connectivity in a dedicated, switch-to-switch configuration. The two-port GigaStack GBIC allows customers to deploy the GigaStack GBIC with various performance and cabling options.

Features

This section describes the GigaStack GBIC features:

Half-duplex stacking using only one GBIC slot for each switch Stack up to nine switches to form an independent backbone that can be managed with a single IP address. This stack gives the appearance of a single large switch for network management purposes.

Full-duplex connectivity between two switches You can also form a point-to-point link between two switches. The GigaStack GBIC supports one full-duplex link (in a point-to-point configuration) or up to eight half-duplex links (in a stack configuration) to other Gigabit Ethernet device.

Support for redundant loop configurations in a GigaStack GBIC stack Management through the Cisco IOS command-line interface (CLI) or the web-based

Cluster Management Suite (CMS) Field-replaceable

4. D-LINK DES-3226switch

D-link switch

D-Link’s DES-3226 is a high-performance, managed, stackable Layer 2 Switch that provides an ideal solution for workgroups and departments. The DES-3226 has (24) 10/100Mbps Fast Ethernet ports with support for optional GBIC modules for fast connection speeds and flexibility. The DES-3226 now supports stacking of up to 8 units per stack. A single stack of DES-3226 can support up to (192) 10/ 100Mbps ports with an additional 8 open GBIC slots available for trunking. The entire stack can be managed via a single IP address for simplified network administration.

Utilizing an 8.8Gbps switch fabric and support for 8,000 MAC addresses, the DES-3226SM is a wire- speed, high performance switch ideal for workgroups or departments. The DES-3226SM supports port trunking with up to 8 trunk groups per stack. Port trunking enables business users to increase availability and aggregated bandwidth between servers and/or other switches, optimizing the transport of all of your business critical data. The DES-3226 utilizes an integrated 1Gbps stacking mechanism for interconnecting units within a stack and open GBIC slot for support for a wide range of GBIC modules.

Specifications (24) Ports 10/100BASE-T, Includes Stacking Ports and Open GBIC Slot MAC Address Table Size

8,000 Switch Fabric

8.8Gbps Switching Capacity Transmission method

Store-and-Forward Spanning Tree Support

802.1d and 802.1w Support VLANs

Supports Up To 255 Dynamic/ 64 Static VLAN Groups (Port Based, Asymmetric Port Based, 802.1q and GVRP)

Access Control Lists L2/L3/L4 Filtering Rules Based On MAC Address, IP Address, and/or TCP/UDP Port Numbers

Link Aggregation 802.3ad and LACP Support

Port Security Port Lock Down To MAC Address

GBIC Stacking Mechanism Supports 8 Units Per Stack, Max Config: (192) 10/100BASE-T Port, (8) Stacking ports & (8) Open GBICs Slots

IGMP Snooping Supports Up To128 L2 Multicast Groups

Interface OptionsRJ-45 10BASE-T, 100BASE-TX & 1000BASE-T

Network Protocol and StandardsIEEE 802.3 Ethernet, 802.3u Fast Ethernet, 802.1d Spanning Tree, 802.1w Rapid Spanning Tree, 802.1p Priority Tags, 802.1q VLANs, 802.1ac VLAN Tagging, 802.1ad Link Aggregation Control, 802.3x Flow Control,802.1x Port Based Network Access Control, and 802.1x MAC Based Network Access Control IEFT RFC 1157 SNMP, RFC 1112/2236 IGMPv1/2, RFC 1757 RMON (4 Groups), RFC 1493 Bridge MIB, RFC 1213 MIB II, RFC 793 TCP, RFC 826 ARP, RFC 854 Telnet and DiffServ.

Power Supply 100-240VAC, 50/60 Hz Internal universal power

5. CISCO CATALYST 2960 Switches

CISCO 2960 Switches

The CiscoCatalyst2960 Series Switches are stand-alone fixed-configuration switches offering Fast Ethernet and Gigabit Ethernet connectivity with LAN services for midmarket and branch office networks.Cisco Catalyst 2960 Series Intelligent Ethernet switches are offered in two categories:• Cisco Catalyst 2960 Series with LAN Base software • Cisco Catalyst 2960 Series with LAN Lite software

Cisco Catalyst 2960 Series Switches with LAN Base software deliver intelligent services for commercial and midsize enterprise wiring closets and branch offices. The LAN Base software supports enhanced integrated security, including Network Admission Control (NAC), advanced quality of service (QoS), availability, and scalable management to enable new converged applications.

Primary Benefits

Connectivity:Fast Ethernet and Gigabit Ethernet connectivity in 8-port, 24-port, and 48-port configurations

Power over Ethernet (PoE): 48 PoE ports, 24 full PoE ports and 24-ports (PoE supported on 8 ports) configurations

Advanced Services:Layer 2 switching with intelligent Layer 2 through 4 services for the network edge such as voice, video, and wireless LAN

Simplified installation, configuration and troubleshooting with ease of use capabilities such as Auto Smart Ports and DHCP Auto Install

Security:Network security enabled through a wide range of authentication methods, data encryption technologies, and NAC based on users, ports, and MAC addresses

QoS and Multicast:Industry-leading mechanisms for marking, classification, and scheduling to deliver superior network performance

Hardware-based multicast services for corporate communications, E-learning, IP video surveillance, high definition video, and distribution of data to desktops in a scalable, reliable and efficient manner

Management:

Cisco Network Assistant simplifies configuration, upgrades, and troubleshooting; Express Setup is quick and easy using the webpage interface

Single IP address, SYSLOG, SNMP management for a stack of up to 16 switches Limited lifetime hardware warranty Software updates at no additional charge

6. Patch panel

Patch Panel

A patch panel or patch bay is a panel, typically rack mounted,that houses cable connections. One typically shorter patch cable will plug into the front side, whereas the back holds the connection of a much longer and more permanent cable.

The assembly of hardware is arranged so that a number of circuits, usually of the same or similar type, appear on jacks for monitoring, interconnecting, and testing circuits in a convenient, flexible manner

Overall College network details

Basic description

1. The college network gets its internet connection from Tata Communications via a 10Mbps dedicated bandwidth. It also has a backup ISP viz. Tulip with a dedicated bandwidth of 2 Mbps.

2. Fiber optic cable is used to connect ISP to the college. So this cable runs from the ISP to a CISCO ASA 5510 firewall.From this point, bandwidth is distributed throughout the college.

3. To ensure privacy of data within the college, two devices are used; the CISCO ASA 5510 and ALLOT. There are certain rules and policies set within these devices which control and hence regulate the smooth flow of data.

4. Within the college Class B IP addresses are used.5. The two hostels-BayaKarve Hostel and Divekar Hostel are equipped with internet

connection. BayaKarve Hostel obtains this connectivity from the main building via Motorola Access points which are three to be precise. Also, the divekar Hostel is wired to the mechanical building from where it gets internet connectivity.

6. All departments in the college are connected to a CISCO layer-3 switch which is kept in the main building on the 3rd floor.

7. The network makes use of VLANS to ensure privacy and easy configurability of the network. This process involves creation of access control lists(ACL) and specifying actions to be performed on packets such as deny,drop or allow and also puts some time constraints on the access of some websites etc.

Architecture

1. All the five floors in the main building are connected to internet. There is a fiber optic cable that runs between the floors and terminates on the third floor where the main switch rack resides.

2. This fiber optic cable is 62.5 micron thick. On every floor there is a connection between this optic cable and an LIU (Light Interface Unit)

3. A SCST cable connects the LIU to the switch rack on that floor which houses several 24 port switches.

4. The switch rack contains many switches (DLINK DES32268). This is a regular 24 port switch with 10/100 ports.

5. There is a jack panel per switch. The use of jack panel ensures ease of fault isolation and maintenance. This is because the jack panel is a passive device and is easier to test in case of some problems of breakdown.

6. There is another module added to every switch. It is called DES 332 GS. It provides one stacking port and one GBIC module. Thus another single PC can be connected ad hoc.

7. Since switches are active devices, they cannot be shut down unless for maintenance. Hence, to keep the switches active at all times, a battery backup is provided on every floor.

8. Thus, from a work area, typically a computer in some lab, there is a connection to the nearest information outlet, then to the switch rack on that floor, then to the main switch on the 3rd floor.

9. In addition to this, there are blade servers kept on the 3rd floor which facilitate some specific functions along with storage of data (upto 5 TB). The advantages of these servers are:

a. Form factor is very less.b. Less space requiredc. Hard disks are hot swappabled. Easily expandablee. Operates on a single power supply.

The blade servers that are used are HP Blade servers (20p Intel Xeon 3.2 Ghz)with L2 cache,2 Gb ram,&2 Gb HDD.

References

Backbone network

1) http://en.wikipedia.org/wiki/Backbone_network 2) http://www.computerhope.com/jargon/b/backbone.htm 3) http://searchtelecom.techtarget.com/definition/backbone 4) http://etidweb.tamu.edu/cdrom3/CHAPTER8.PDF 5) http://www.wiley.com/college/dennis/0471201898/ppt/ch05.ppt

Patch panel

6) http://serverfault.com/questions/42899/what-is-a-patch-panel 7) http://en.wikipedia.org/wiki/Patch_panel

Network Components

8) http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps5023/ prod_brochure0900aecd803ca7c6.pdf - CISCO 3750 Switch

9) http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps6406/ product_at_a_glance0900aecd8047794c.pdf - CISCO catalyst 2960

10) -GBIC11) http://www.cisco.com/en/US/prod/collateral/vpndevc/ps6032/ps6094/ps6120/

product_data_sheet0900aecd802930c5.html- CISCO ASA 551012) http://www.dlink.com/-/media/Business_Products/DES/DES%203226SM/datasheet/

DES%203226SM_Datasheet_EN_US.pdf - Dlink switch