Cox Business garners MEF 14 certification

By Mike Robuck CedMagazine.com - April 29, 2008

Cox Business said today that it has received certification from the Metro Ethernet Forum for MEF 14.

Service providers that attain MEF 14 certification have the ability to offer quality of service (QoS) for Ethernet services, backed by service level specifications.

Cox Business, a division of Cox Communications, is currently ranked fourth among U.S. Ethernet providers, above several incumbent providers, according to Vertical Systems Group's Year-End 2007 U.S. Retail Business Ethernet share analysis.

Cox Business became the first MSO to enter the top tier of U.S. business Ethernet providers in 2007 (story here). Cox Business attributed its aggressive growth to its history of delivering Ethernet services to customers served by both fiber and hybrid fiber/coax (HFC).

"Ethernet-based services are extremely flexible and efficient, and MEF 14 certification further demonstrates Cox's commitment to this technology," said Kristine Faulkner, VP of product development and management for Cox Business. "Cox's network uniquely aligns with this preferred transport platform to offer compelling data services throughout our service areas that meet a variety of business needs."

More Broadband Direct:

• Cox buys Adify to get into online ad sales

• Comcast boosts business-class broadband speeds to 16 Mbps

• Charter boosts broadband speed in Wis. footprint

• Cox Business garners MEF 14 certification

• Verizon phasing out duplicate analog channels in Mass.

• ICTV, Camiant wrap up interactive testing

• Report: VoIP growth will be pressured by wireless

• Embarq chooses Ciena's CN 4200 to up bandwidth

• Adva products make carrier Ethernet easier

• Broadband Briefs for 4/29/08

When homes get 50-100 Mbps, a slew of high-definition content, better-quality video-sharing sites and even 3-D video will be enabled. Call it Broadband 2.0, says Wired.

Experts say this increased bandwidth — when it becomes widely available — will have a profound effect on everything from our social interactions on the web to the way we consume media.

“The YouTube philosophy is really the primary motivator here,” says Connie Chang-Hasnain, a professor of electrical engineering at the University of California at Berkeley and expert in broadband communications. “Even grandmas post things on YouTube. But, right now, the resolution is terrible and there are some very predefined limits due to bandwidth.”

All of that will change with 50 Mbps download speeds, she said, and by simply improving the sound and video quality of video streaming sites, you can dramatically change how a society learns, teaches and communicates.

“Basically, people are going to do a lot of the things they normally do today, but in a better, more satisfying, way,” says Crick Waters, co-founder of Ribbit, a Silicon Valley company that sells an internet-based telephony platform.

Waters says that first and foremost, we can expect everything to go high-definition: We’ll download HD movies from Netflix, upload HD content to YouTube, and watch more sophisticated HD content on our televisions. The added bandwidth may even spur development of extra goodies, like stereoscopic 3-D video and high-fidelity audio.

“Believe me, the minute someone puts the pipes out there, people will find a way to use them,” Waters says.
 

Comcast and Verizon have both started offering ultra-high-bandwidth services to select customers. Comcast’s new cable modem technology delivers 30-50 Mbps, while Verizon’s FiOS service delivers via optical fibers.

Both services are currently available only in relatively limited geographic areas. Earlier this month, Comcast started offering a service to some Minneapolis/St. Paul residents that features download speeds of 50 Mbps for a hefty $150 a month. Comcast CEO Brian Roberts (video tour of new building) said his company plans to expand this new service in 20 percent of the area it serves by the end of the year, as well as offer speeds in excess of 100 Mbps in two years.

Verizon currently offers FiOS in parts of 17 states. Verizon said it will offer its fiber-to-the-home services to more than 18 million people — half of the geographic area it now serves — by 2010. Meanwhile, seeing no signs that the slowing economy is crimping consumer spending, Verizon plans to raise prices on its TV service.

AT&T on Friday denied using forged reset packets to interfere with file-sharing users, as Comcast has been accused of doing with BitTorrent traffic. Comcast has admitted to delaying “excessive” peer-to-peer file-sharing traffic at “peak hours” of network congestion. Comcast has since pledged to migrate to a “protocol agnostic” network management technique by the end of the year.

Portland officials are considering a $500 million municipal fiber network.

City officials claim Comcast — Portland’s primary broadband provider — is charging too much and offering speeds too slow to compete on a national and global level.

Qwest DSL, which previously topped out at 7 mbps, is now available at 12 mpbs and 20 mbps in Portland, Vancouver, Salem, Eugene and Bend. But the faster speeds aren’t available in all parts of those cities.

Qwest’s Chief Technology Officer Pieter Poll told Telephony that VDSL2 bonding, which couples two twisted pairs, can bring speeds up to 30-40 Mbs, and may be available in 2009.

According to city studies, Portland residents pay the same monthly fees for half the internet speed as the national average. Comcast, not surprisingly, disagrees, and points to a different study (pdf). David Olson, the cable director of Portland, believes that the only way to bring fast, affordable internet access to all residents is to essentially make broadband internet a public utility (Think Out Loud, MP-3).

The SLC Tribune, which has often editorialized against Utopia, says the municipal fiber system still struggles for financial footing. But the munifiber system in The Dallas, Oregon attracted Google.

Here is Portland’s RFI for a Portland FIBER-TO-THE-PREMISES system.

Dynamic Host Configuration Protocol (DHCP) 

 

In the late 1980s, the IETF recognized that the useful life of the current version of IP, Internet Protocol Version 4 (IPv4), would not last forever. Address space, in particular, was cited as IPv4’s biggest weakness; although a 32 bit address should allow us to identify up to four billion hosts, hierarchical address structures, such as the one used with IP, have inefficiencies that result in addresses running out. In 1991, work began on the next generation of IP, dubbed IPng. The goal of the IPng work was to define a successor to IPv4. While still quite usable and implemented on the current Internet, IPv4 has been showing its age in a number of areas and a replacement protocol is needed. Through many iterations and proposals, IP Version 6 (IPv6) was officially entered into the Internet Standards Track in December, 1995.

According to the IPv6 specification, the changes from IPv4 to IPv6 fall primarily into the categories listed below.

• Expanded Addressing Capabilities: IPv6 increases the IP address size from 32 bits to 128 bits to support more levels of addressing hierarchy, a much greater number of addressable nodes, and simpler auto-configuration of addresses. The scalability of multicast routing is improved by adding a Scope field to multicast addresses. A new type of address, called an anycast address, is defined; it is used to send a packet to any one of a group of routers.

• Header Format Simplification: Some IPv4 header fields have been dropped or made optional, to reduce the common-case processing cost of packet handling and to limit the bandwidth cost of the IPv6 header.

• Improved Support for Extensions and Options: Changes in the way IP header options are encoded allow more efficient forwarding, less stringent limits on the length of options, and greater flexibility for introducing new options in the future.

• Flow Labeling Capability: A new capability is added to enable the labeling of packets belonging to particular traffic flows for which the sender requests special handling, such as non-default quality of service or real-time service.

• Authentication and Privacy Capabilities: Extensions to support authentication, data integrity, and data confidentiality are specified for IPv6. These features will increase security while actually reducing the security effort. Authentication performed on an end-to-end basis during session establishment will actually provide more secure communications, even in the absence of firewall routers.

IPv6 Addresses

To accommodate almost unlimited growth and a variety of addressing formats, IPv6 addresses are 128 bits long. One IETF member has suggested that this address space is sufficient to uniquely address every molecule in our solar system! There are three types of IPv6 addresses.

Unicast

An address for a single interface. A packet sent to a unicast address is delivered to the interface identified by that address.

Anycast

An address for a set of interfaces (typically belonging to different nodes). A packet sent to an anycast address is delivered to one of the interfaces identified by that address; usually the “nearest” one according to the routing protocol’s measure of distance.

Multicast

An identifier for a set of interfaces (typically belonging to different nodes). A packet sent to a multicast address is delivered to all interfaces identified by that address.

There are no broadcast addresses in IPv6 since their function is provided by multicast addresses.

IPv6 multicast addresses provide an identifier for a group of nodes. A node can belong to any number of multicast groups. Multicast addresses might not be used as a source address in IPv6 datagrams or appear in any routing header.

Multicast addresses, as shown on the accompanying visual, begin with eight ones (0xFF). The next four bits are a set of flag bits; the three high-order bits are set to zero and the fourth bit (T-bit) indicates a permanently assigned (“well-known”) multicast address (T=0) or a non-permanently assigned (“transient”) multicast address (T=1). The following four bits are the scope, used to limit the extent of the multicast group; assigned scope definitions (and hex values) are reserved (0 or F), node-local (1), link-local (2), site-local (5), organization-local (8), or global (E).

The remaining 112 bits are the group identifier, which identifies the multicast group, either permanent or transient, within the given scope. The “meaning” of a permanently assigned multicast address is independent of the scope value. For example, if the “SMTP servers group” is assigned a permanent multicast address with a group ID of 0×43, then:

• FF01:0:0:0:0:0:0:43 means all SMTP servers on the same node as the sender.

• FF02:0:0:0:0:0:0:43 means all SMTP servers on the same link as the sender.

• FF05:0:0:0:0:0:0:43 means all SMTP servers at the same site as the sender.

• FF0E:0:0:0:0:0:0:43 means all SMTP servers in the Internet.

A number of well-known multicast addresses are predefined, including those listed below.

• Reserved Multicast Addresses: Reserved and never assigned to any multicast group. These addresses have the form FF0x:0:0:0:0:0:0:0, where x is any hex digit.

• All Nodes Addresses: Identify the group of all IPv6 nodes within the given scope. These addresses are of the form FF0t:0:0:0:0:0:0:1, where t =1 (node-local) or 2 (link-local).

• All Routers Addresses: Identify the group of all IPv6 routers within the given scope. These addresses are of the form FF0t:0:0:0:0:0:0:2, where t =1 (node-local) or 2 (link-local).

• The DHCP Server/Relay-Agent Address: Identifies the group of all IPv6 DHCP servers and relay agents with the link-local scope; this address is FF02:0:0:0:0:0:0:C.

IPv4 Addresses in IPv6

Although it is not certain when the Internet will move to IPv6, it is certain that when it does the Internet will slowly migrate to IPv6 addressing.

The IPv6 transition mechanisms include a technique for hosts and routers to dynamically tunnel IPv6 packets over the IPv4 routing infrastructure. IPv6 nodes that utilize this technique are assigned special IPv6 unicast addresses that carry an IPv4 address in the low-order 32 bits, as shown on the accompanying visual.

IPv4 addresses are carried in a 128 bit IPv6 address space that begins with 80 zeros (0:0:0:0:0). The next 16 bits indicate the IPv4–IPv6 address compatibility, or the way in which the host/router handles IPv4 and IPv6 addresses.

If the device can handle either IPv4 or IPv6 addresses, the compatibility bits are all set to zeros (0); this type of address is termed an “IPv4-compatible IPv6 address.” If the address represents an IPv4-only node (i.e., one that does not support IPv6), the compatibility bits are all set to one (FFFF) and the address is termed an “IPv4-mapped IPv6 address.”

An IPv6 mapped address is an IPv4 address transported over an IPv6 network. If a user with a machine configured for IPv4 wants to communicate with a server on the Internet that is using IPv6, the packet reaching the server contains an IPv6 mapped address. A compatible address, on the other hand, is an IPv6 address that is meant to be used when communicating with an IPv4 network. In this example, the user uses an IPv6 protocol stack trying to communicate with a server running IPv4. In this case the IPv6 address must either be compatible from the start, or be translated at some point into an IPv6-compatible address.

The remaining 32 address bits contain a 32 bit IPv4 address in dotted decimal notation.

IPv6: The Reality

While IPv6 was developed to address a number of Internet deficiencies, it probably will not be adopted as the standard implementation of IP anytime soon. The major concern about IPv4 was the depletion of address space, but classless interdomain routing (CIDR), Dynamic Host Configuration Protocol (DHCP) and Network Address Translation (NAT) have all played a part in reducing the rate of address depletion. IPv6 offers several other advantages over IPv4, many of which can be migrated into IPv4. While this might be costly, it will likely be less costly than changing to IPv6. Fred Baker, chairman of the IETF, once indicated there could be another (better) replacement for IPv4 by the time address depletion becomes a real problem.

In the meantime, several tools are available to help organizations migrate to IPv6. These include translation systems to map IPv6 to/from IPv4 at a gateway between the two. Many vendors are still pushing IPv6 technology despite the lackluster response from the Internet world.

An IPv6 worldwide testbed called the 6bone has been operating since 1996. You can find more information about the 6bone on the Internet at http://www.6bone.net.

Microsoft made the technical preview of IPv6 available for software developers for use with Windows 2000. The code and related information were made available for download in March 2000.

Cisco Systems has IPv6 code present in its IOS. IPv6 is being added to the DNS systems of a number of countries.

IPv6 Header Format

• Version: Internet Protocol version number; coded 0×6 (4 bits).

• Traffic Classes: Enables a source and/or forwarding router to identify and distinguish among different classes or priorities of IPv6 packets.

• Flow Label: How a source identifies packets that need special handling, such as non-default quality of service or real-time service (20 bits). A control protocol such as the Resource * * * Reservation Protocol (RSVP) or information within the flow packets themselves, such as hop-by-hop option, might convey the nature of the special handling to the network routers. There may be multiple active flows from a source to a destination, as well as traffic that is not associated with any flow (i.e., Flow Label = 0). The combination of a source address and a nonzero flow label uniquely identifies a flow.

• Payload Length: Payload length (i.e., the portion of the packet following the header), in octets (16 bits). Its maximum value is 65,535; if this field is zero, it means that a larger payload is enclosed and the actual payload length value is carried in a Jumbo Payload, hop-by-hop option.

• Next Header: Identifies the type of header immediately following the IPv6 header; uses the same values as the IPv4 Protocol field, where applicable (8 bits). Possible values include 1 (ICMP), 6 (TCP), 17 (UDP), 58 (ICMPv6), and 89 (OSPF).

• Hop Limit: Specifies the maximum number of hops that a packet may take before it is discarded (8 bits). It is set by the source and decremented by 1 by each node that forwards the packet. The packet is discarded if the hop limit is decremented to zero. This field was renamed from IPv4’s Time to Live (TTL) field because the value limits the number of hops, not the amount of time that a packet can stay in the network.

• Source Address: IPv6 address of the originator of the packet (128 bits).

• Destination Address: IPv6 address of the intended recipient of the packet (128 bits).

IPv6 Address Representation

There are three conventional forms for writing out IPv6 addresses. The preferred, or regular, form is to write out the hexadecimal values of the eight 16 bit blocks of the address, separated by colons (:), in the form x:x:x:x:x:x:x:x, where each x represents a 16 bit hexadecimal value. An example might be 1080:805:FF32:5:17:200C:7654:20. Note that it is not necessary to write leading zeros in a field, but there must be at least one numeral in every field.

Because of the way in which addresses are allocated in IPv6, addresses will frequently contain long strings of zeros. To make the task of writing addresses containing many zero bits less onerous, a shorthand syntax, or compressed format, has been defined. Specifically, the double colon (::) string can be used to indicate multiple groups of 16 bits of zeros. As an example, the address FF01:0:0:0:0:0:0:43 could be written as FF01::43. To avoid ambiguity, the “::” can only appear once in an address.

Finally, an alternative format for mixed IPv6/IPv4 addresses has been defined to make it more convenient (and less error prone) when representing an IPv4 address in an IPv6 environment. Specifically, the first 96 address bits (six groups of 16) are represented in the standard IPv6 format (x:x:x:x:x:x), the remaining 32 address bits are represented in common IPv4 dotted decimal; this is denoted x:x:x:x:x:x:d.d.d.d where each x represents a 16 bit hex value and each d represents an 8 bit decimal value. Examples of this nomenclature include 0:0:0:0:0:0:199.182.20.17 or ::FFFF:15.0.100.18.

Well it is finally coming… Are you ready Tucson?

Data Over Cable Service Interface Specification

Data Over Cable Service Interface Specification (DOCSIS) is an international standard for the exchange of packets across a community antenna television (CATV) transmission infrastructure. Today, that means the hybrid fiber/coax networks deployed by the cable television companies. Developed by CableLabs (and a variety of contributing companies), DOCSIS defines the protocol relationship between a cable modem and a cable modem termination system (CMTS).

Originally intended to support the addition of broadband Internet services to existing CATV systems, today DOCSIS also supports the addition of packet voice and other real-time applications.

DOCSIS Evolution

The first DOCSIS standard was DOCSIS 1.0, which was released in March of 1997. In April of 1999, DOCSIS 1.1 was introduced. It's primary enhancement was the addition of Quality of Service (QoS) to support real-time applications. DOCSIS 2.0 was introduced in December 2001 and primarily focused on enhancing upstream speeds to support symmetric applications. The latest version, DOCSIS 3.0, was published in August of 2006. It's primary enhancements included support for IPv6 and enhanced transmissions speeds to support the increasingly bandwidth hungry applications supported in the Internet.

Although the standards are international in scope, there are variants of the standards in Europe and Japan. These variants primarily address the differences in spectrum allocation within the various countries.

DOCSIS and the OSI Reference Model

If the DOCSIS specifications were aligned with the OSI Reference Model (OSI-RM), they would align with Layer 1 (Physical Layer) and Layer 2 (Data Link Layer). DOCSIS provides great variety in options available at Open Systems Interconnection (OSI) layers 1 and 2, the Physical (PHY) and Media Access Control (MAC) layers.

Physical Layer Issues

Because DOCSIS runs over the HFC network, and has to co-exist with the video channels on that plant, the Physical Layer is somewhat constrained. The downstream channel occupies channels that would otherwise be used for digital video signals. The upstream channels reside in the lowest frequencies of the HFC cable plant (e.g., below 50 MHz). The earliest DOCSIS standards (1.0, 1.1) specified channel widths between 200 kHz and 3.2 MHz for the upstream component. With DOCSIS 2.0, this was widened to 6.4 MHz (although it remains backwards compatible to the earlier versions). Increase in the upstream path was critical to supporting symmetric services.

Channel width, however, is only one part of total carrying capacity. Modulation is another part. Prior to DOCSIS 2.0, modulation was 64-QAM or 256-QAM downstream and QPSK or 16-QAM upstream. DOCSIS 2.0 added 32-QAM, 64-QAM and 128-QAM as upstream options. Which is actually used is a function of the quality of the specific cable plant and can be auto-negotiated by the end points. Although DOCSIS 3.0 provides for higher throughput, it doesn't do so by altering the modulation scheme. Instead, it takes the higher-layer approach of logically bonding multiple data streams at the packet level. In other words, if one channel provides 30 Mbps downstream, two bonded channels should scale to 60 Mbps.

Data Link Layer Issues

It is important to remember the nature of the HFC cable plant. The CMTS sits at the head end of the plant and essentially functions as a router injecting packets into the HFC plant for distribution to the subscribers, and accepting packets from the subscribers nodes for injection into Internet, voice, or transport data services. So there is a one-to-many relationship between the CMTS and the cable modems, and a many-to-one relationship between the cable modems and the CMTS. There is no real need for access control downstream, but there is a need for addressing. On the other hand there is a critical need for access control upstream. DOCSIS provides for both of these at the Media Access Control (MAC) layer.

DOCSIS 1.0 and 1.1 specified the use of Time Division Multiple Access (TDMA). DOCSIS 2.0 also supports TDMA but adds Synchronous Code Division Multiple Access (SCDMA) as an option. In both standards, there is contention resolution mechanism for upstream access control. Because the CMTS controls the facility, DOCSIS can implement a form of contention-based access control that is far less prone to collisions than the CSMA/CD scheme implemented in early (shared bandwidth) Ethernet networks. It is also the MAC Layer that provides mechanisms to support differing QoS in the same data channel.

DOCSIS Throughput

Downstream, all versions of DOCSIS have supported either 30 Mbps per channel (64-QAM) or 43 Mbps (256-QAM). DOCSIS 3.0 achieves higher rates by combining channels at the packet level.

Upstream, however, the standards differ dramatically. Use of QPSK supports upstream data rates in all DOCSIS versions up to about 5 Mbps. Use of 16-QAM boosts that to as much as 10 Mbps, also in all versions of DOCSIS. The introduction of 64-QAM coupled with changes in access control options in DOCSIS 2.0 (supported in DOCSIS 3.0) increases potential throughput to as high as 30 Mbps.

DOSCIS Security

Because the HFC network is intrinsically a shared infrastructure, DOCSIS has to address security concerns. Specifically, it has to ensure that consumer information is kept secure from other subscribers, and it has to protect the service provider from unauthorized access to network services. To do this, DOCSIS defines a security capability in something called the Baseline Privacy Interface (BPI) specifications. BPI was improved in DOCSIS 1.1 and 2.0, and the new version was dubbed Baseline Privacy Interface Plus (BPI+). As part of the DOCSIS release, several enhancements were added and the BPI/BPI+ specification was renamed simply Security (SEC).

To provide for data privacy, BPI/SEC encrypt traffic between the CMTS and the cable modem. BPI and BPI+ specified the use of 56-bit Data Encryption Standard (DES) encryption. SEC added support for 128-bit Advanced Encryption Standard (AES). All three specifications support a key refreshing interval that can be configured by the service provider. The original BPI did not have a key management protocol that authenticated the cable modems. BPI+ and SEC are stronger because they feature authentication based on digital certificates and a public key infrastructure.
 

The first networks to use fiber to connect to consumers were deployed by the cable companies. They migrated from pure coaxial cable entreats to hybrid fiber/coax (HFC) entreats. HFC gives the cable company the ability to push more bandwidth to the customer over greater distances. Primary drivers for this approach are listed below.

• The increase in the number of TV channels available
• The move to digital cable
• Cable modem services
• Video on demand (VOD)

All of these require the companies to increase the bandwidth the customer receives.

Cable modem services have proven to be a lucrative addition to the service portfolio. Demand for high-speed Internet access has been significant. Today high-speed Internet access accounts for a significant percentage of cable company revenues.

To stay ahead of the bandwidth curve, new HFC architectures with DWDM are appearing. Headend functions are centralized for a metro area to a single master headend. Programming and data services are distributed to hubs, which in turn pass the services on to nodes. In large metro areas there may be two levels of hubs in the architecture.

With the advent of VoIP products some cable companies are adding voice to the services offered. Voice is provided via a gateway device connected to the home WAN.