1.2 Topologies And Network Types Flashcards
SDWAN
• Software Defined Networking in a Wide Area Network
– A WAN built for the cloud
• The data center used to be in one place
– The cloud has changed everything
• Cloud-based applications communicate directly to the cloud
– No need to hop through a central point
MPLS
Multiprotocol label switching
Learning from ATM and Frame Relay
• Packets through the WAN have a label– Routing decisions are easy
• Any transport medium, any protocol inside
– IP packets, ATM cells, Ethernet frames
- OSI layer 2.5 (!)
• Increasingly common WAN technology
– Ready-to-network MPLS pushing and popping
• Labels are “pushed” onto packets as they enter the MPLS cloud
• Labels are “popped” off on the way out
mGRE
• Multipoint Generic Router Encapsulation
– Used extensively for Dynamic Multipoint VPN (DMVPN)
– Common on Cisco routers
• Your VPN builds itself– Remote sites communicate to each other
• Tunnels are built dynamically, on-demand– A dynamic mesh
NFV
Network function virtualization
• Replace physical network devices with virtual versions
– Manage from the hypervisor
• Same functionality as a physical device
– Routing, switching, load balancing, firewalls, etc.
• Quickly and easily deploy network functions
– Click and deploy from the hypervisor
• Many different deployment options
– Virtual machine, container, fault tolerance, etc.
Hypervisor
• Virtual Machine Manager
– Manages the virtual platform and guest operating systems
• Hardware management
– CPU, networking, security
• Single console control
– One pane of glass
Type 1 (bare-metal)
Hardware -> Hypervisor -> Guests
Type 2 (hosted)
Hardware -> Host OS -> Hypervisor -> Guests
DSL (provider link)
Digital subscriber line
• ADSL (Asymmetric Digital Subscriber Line)
– Uses telephone lines
• Download speed is faster than the upload speed (asymmetric)
– ~10,000 foot limitation from the central office (CO)
– 200 Mbit/s downstream / 20 Mbit/s upstream are common
– Faster speeds may be possible if closer to the CO
Satellite (provider link)
• Communication to a satellite
– Non-terrestrial communication
• High cost relative to terrestrial networking
– 50 Mbit/s down, 3 Mbit/s up are common
– Remote sites, difficult-to-network sites
• High latency
– 250 ms up, 250 ms down
• High frequencies
- 2 GHz– Line of sight, rain fade
Copper (provider link)
• Extensive installations
– Relatively inexpensive,
– Easy to install and maintain
• Limited bandwidth availability
– Physics limits electrical signals through copper
• Wide area networks
– Cable modem, DSL, T1/T3 local loop
• Often combined with fiber
– Copper on the local loop, f iber in the backbone
Cable broadband (provider link)
• Broadband
– Transmission across multiple frequencies
– Different traffic types
• Data on the “cable” network
– DOCSIS (Data Over Cable Service Interface Specification)
• High-speed networking
– 50 Mbits/s through 1,000+ Mbit/s are common
• Multiple services
– Data, voice, video
Fiber (provider link)
• High speed data communication
– Frequencies of light
• Higher installation cost than copper
– Equipment is more costly and more difficult to repair
– Communicate over long distances
• Large installation in the WAN core
– Supports very high data rates
– SONET, wavelength division multiplexing
• Fiber is slowly approaching the premises
– Business and home use
Metro Ethernet (provider link)
• Metro-E
– Metropolitan-area network
– A contained regional area
• Connect your sites with Ethernet
– A common standard
• The provider network is optical
– Local fiber network
– Wavelength-division multiplexing
– High speed, multiple wavelengths of light
E-LAN
Multipoint deployments were multiple endpoints feel like they are part of the same LAN.
*MAN uses a service category such as an E-line, which establishes a point to point link or E-LAN, which establishes a mesh topology.
