The Internet Protocol (IP) is a protocol used for communicating data across a packet-switced internetwork using the Internet Protocol Suite, also referred to as TCP/IP.
IP is the primary protocol in the Internet Layer of the Internet Protocol Suite and has the task of delivering distinguished protocol datagrams (packets) from the source host to the destination host solely based on their addresses. For this purpose the Internet Protocol defines addressing methods and structures for datagram encapsulation. The first major version of addressing structure, now referred to as Internet Protocol Version 4(IPv4) is still the dominant protocol of the Internet, although the successor, Internet Protocol Version 6(IPv6) is being deployed actively worldwide.
IP (Internet Protocol) is the primary network protocol used on the Internet, developed in the 1970s. On the Internet and many other networks, IP is often used together with the Transport Control Protocol (TCP) and referred to interchangeably as TCP/IP.
IP supports unique addressing for computers on a network. Most networks use the Internet Protocol version 4 (IPv4) standard that features IP addresses four bytes (32 bits) in length. The newer Internet Protocol version 6 (IPv6) standard features addresses 16 bytes (128 bits) in length.
Data on an Internet Protocol network is organized into packets. Each IP packet includes both a header (that specifies source, destination, and other information about the data) and the message data itself.
IP functions at layer 3 of the OSI model. It can therefore run on top of different data link interfaces including Ethernet and Wi-Fi.
IP encapsulation
Data from an upper layer protocol is encapsulated as packets/datagrams(the terms are basically synonymous in IP). Circuit setup is not needed before a host may send packets to another host that it has previously not communicated with (a characteristic of packet switched networks), thus IP is a connectionless protocol. This is in contrast to public switched telephone networks that require the setup of a circuit for each phone call (connection-oriented protocol).Services provided by IP
Because of the abstraction provided by encapsulation, IP can be used over a heterogeneous network, i.e., a network connecting computers may consist of a combination of Ethernet, ATM, FDDI,Wi-Fi or others. Each link layer implementation may have its own method of addressing (or possibly the complete lack of it), with a corresponding need to resolve IP addresses to data link addresses.
- DS-1 (1.54 Mbs)
- Fractional T3
- DS-3 (45 Mbps)
- OC-3 (155 Mbps)
- OC-12 (622 Mbps)
- OC-48 (2.5 Gbps)
- OC-192 (10 Gbps)
- 100BT/Fast Ethernet (100 Mbps)
- 1000SX/GigabitEthernet (1000 Mbps)
- 10 Gigabit Ethernet
Access Methods
Level 3 IPS offering includes a variety of access methods, including dial up, private line, broadband, and UNI connections with existing frame relay and ATM networks:
- Analog Dial-up
- Private Line/ SONETS
- Ethernet
Peering Arrangements
Level 3 has established peering relationships worldwide. These include both public and private peering. Relative to the shared switched fabric connecting networks in public exchanges, private peering provides improved performance and scalability. Level 3’s private peering connections are OC-48, OC-192 or 10 GigE. Approximately 95% of Level 3’s interconnection traffic runs through private interconnections. Private interconnects provide the best possible performance between Level 3 and other Tier 1 backbones.
IP Addresses and Domain Names
Level 3 IPS supports IP address assignment and domain name service. IP network numbers are globally governed by the Internet Assigned Numbers Authority (IANA). IANA in turn delegates authority for some parts of the IP address space to regional Internet registries. Although assigned to the customer for the duration of its service contract with Level 3, all Level 3-assigned IP network numbers remain an integral part of Level 3’s contiguous range of addresses and must be relinquished by the customer when service expires or is terminated. Customers who require or desire IP address portability must apply for IP network numbers directly from the appropriate registry. For customers who have legally assigned IP network numbers that they wish Level 3 to route as part of IPS, Level 3 will accept routing of those IP network numbers on behalf of these customers. For customers requesting that Level 3 route IP network numbers belonging to another ISP’s address space, Level 3 requires written permission from that ISP to route those network numbers on the customer’s behalf. For broadband access, the Level 3 Team offers both Dynamic Host Configuration Protocol (DHCP) and static IP options. Some DSL services may be a point-to-point Protocol over Ethernet (PPPoE) variant of DHCP. Sometimes it may not be possible, or desirable, to install a PPPoE software stack on an end user’s PC. In these cases, the Team will deploy secondary CPE (router and/or hub) for purposes of authenticating a PPPoE session.
Domain Name Service
Domain name registration service includes the administrative tasks of originating unique domain names with an ICANN-accredited registrar. Level 3 will assist the customer with submission of the appropriate information to register chosen domain names. However, the customer is responsible for actual submissions to the registrar, all registration fees, ongoing maintenance charges, and modifications to the domain names. These are the direct responsibility of the customer, as dictated by the domain registrar. Level 3 provides primary name server support for its customers. In this service, Level 3 establishes and manages primary zone records for the customer’s domains on one of Level 3’s name servers. Once established, Level 3 performs zone record changes during normal business hours and limits these changes to one per week (on average). Level 3 attempts to implement customer change requests within one business day. Level 3’s name servers are located at physically separate facilities within the United States and are connected to Level 3’s backbone at different points. Level 3 also provides secondary name server support for its customers. In this service, Level 3 establishes and manages zone transfers with the primary name server keeping the master zone records. Zone transfers will not occur more frequently than once per hour. Customers can elect for Level 3 to support secondary name services or both primary and secondary name services.
Border Gateway Protocol (BGP) Support
Static routing is the standard configuration for those customers with a single Internet connection. BGP4 routing is supported for customers with connections to multiple Level 3 Gateways or customers with connections to both Level 3’s and other ISPs’ networks. Customers may provide their own registered Autonomous System (AS) Number or may use a Level-3-provided, private AS when the customer is multi-homed only to Level 3.
Benefits
Many companies attempt to integrate multiple legacy systems to create one complete network. These “patchwork” systems create many difficulties when problems must be controlled or when the source of a problem must be located. Level 3 is unencumbered by legacy networks and is able to more easily and more rapidly scale our network. This provides for a faster deployment of new technologies. The Level 3 IPS consistently provides outstanding performance, including best-in-class latency, outstanding availability, very low packet loss, and fast service restoration. Level 3 repeatedly receives top marks in reputation and quality from both our customers and third-party analysts. Level 3 built its entire IP Core North American network from the ground up. Optronics and optical fiber are uniform throughout. We maintain complete operations and management control over the network. The result is fewer variables when troubleshooting, which enables us to provide to the Government highly reliable and available IP-based services.
Alternative Services:
- SONETS
- CHS
- NBIP-VPNS
Restrictions:
- None
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