Gettin’ Jiggy with Gig-E: Part 1
by Leslie Ellis // June 24 2002
Most who cleave to technological matters are occasionally guilty of making nouns out of verbs, like saying “transport” to describe things that move signals from one place to another. It goes like this, conversationally: “It’s part of the transport,” or “it’s a transport issue.”
In cable, when people say “transport,” they mean the devices and paths linking headends and distribution hubs, more so than they mean the “last mile” of coaxial cable conveying signals to homes.
Distribution hubs are part of cable’s regional network. They connect the headend to the last mile. One hub generally serves around 200,000 homes passed, and from it, signals are sent to smaller, 500-ish home nodes. Other industries would call this region a “metropolitan area network.” Links between a headend and its distribution hubs can span a few kilometers, or 40 kilometers, depending on geography.
“Transport” discussions invariably evoke the brainiac language of fiber optics: Wave division multiplexing (WDM), and dense wave division multiplexing (DWDM), for example. Both shove more bits into more “colors” of light, along the same fiber optic cable.
Despite the waning mound of capital dollars earmarked for network rebuilds and upgrades in U.S. cable systems, suppliers of transport equipment are always coming up with new paraphernalia. Using it, mercifully, doesn’t involve digging up streets. It usually means changing out the smallish metal boxes on each end of an installed length of fiber.
The logic works: Keep the expensive part of the investment right where it is. (The expensive part of building a shiny, new, $30,000 mile of hybrid-fiber coax plant is the labor required to suspend or bury cables.) Boost the ends with better stuff that can either accommodate more, go further, or both.
The new stuff of today’s transport discussions is “gigabit Ethernet.” Its shortened version is “Gig-E,” as in, rhymes with ziggy. “Giga” means billion, so a “gigabit” is a billion bits transmitted each second. A bit is digital’s lowest common denominator. It’s the one or the zero, essentially – a binary digit, minus the “nary” and the “digi.”
Which brings us to the Ethernet part of Gig-E.
Conversationally, Ethernet is often the magic, if inscrutable, answer. How does it work, you say. It’s Ethernet, you’re told.
As though saying “Ethernet,” with a solemn, knowing nod, will fill the knowledge gaps and make everything ok.
What is Ethernet? It’s a tried-and-true specification, now 29 years old, for hooking stuff up together to work as a group. It started out with links between PCs and printers in offices, which came to be known as “local area networks.” Ethernet’s identifying characteristics are things like data rate (a billion bits per second, in this case), maximum link length (about 500 meters for coax, and 100 meters for twisted-pair copper), media type (coax, fiber, or twisted pair), and topology (the “shape” of the network – bus, star, point-to-point).
Ethernet also describes how interconnected things communicate. Say you’re a device that speaks Ethernet. You’re at a cocktail party with 30 other Ethernet devices. Mostly, everyone stands, sips, and listens (to nothing, because no one is talking.) Suddenly, you have something to say. If you happen to blurt your packets at the same time someone else is blurting packets, your blurts collide. You stop talking, wait a random amount of time (measured in micro-seconds), then repeat what you said. So does the other person. The random wait interval helps to assure that you don’t collide again.
Couple gigabit speeds with Ethernet, and you’ve got a way to move digital information really fast, from one place to another.
Watch for discussions about Gig-E to heat up in lockstep with the notion of on-demand video, beyond films. Right now, most operators place video servers in multiple distribution hubs, and replicate the contents periodically. The thinking is that there won’t be sufficient storage, nor a way to quickly refresh the servers, when regular television (i.e., not just movies) shifts to on demand.
There’s ample reason to move carefully into Gig-E, our industry’s more cautious technologists suggest. One of the reasons Gig-E is suddenly warming to cable is the meltdown of the competitive local exchange carriers, or CLECs. When your customer base evaporates, you find a new one. Cable is the new one. That doesn’t necessarily mandate the use of Gig-E.
Also, some technologists warn: If it sounds too good to be true, it probably is. Particularly the most common rose that sweetens Gig-E discussions: It’s cheap. Commoditized.
Making sure it’s as cheap as everyone says involves modeling how bandwidth usage may change in the face of an on-demand TV surge. More on that next time.
This column originally appeared in the Broadband Week section of Multichannel News.
Part 2: Billing and Cable’s Transactional Future
by Leslie Ellis // June 10 2002
Last time, we dissected how billing systems became inextricable from the many automated processes that run the cable business, and how that inextricability decelerates new service launches.
(The condensed version, in case you missed it: Nested within the “can we bill for it” question about any new service launch are piles of other questions. From customer acquisition, to workforce administration, to billing and collection, cable’s billing systems are the back office.)
This time, translations on three of the buzzwords that accompany the industry’s inevitable march toward transactional services: Mediation, rating, and settlement.
The shift toward transaction-oriented billing is inevitable because stasis is unacceptable. Or, as the saying goes: If you’re not growing, you’re dying. Business growth usually involves selling more things consumers want; consumers want instant gratification; instant gratification is more point-of-sale than monthly bill.
Which brings us to the heavy reality, again, of how hard it is to launch new services if the billing system isn’t nimble.
Shifting towards a transaction-oriented marketplace is considerably more complicated than, say, tacking $3.99 onto the monthly bill for a pay-per-view event. Maybe it’s deciding on a Monday to offer a free month of subscription video on demand (SVOD) on Friday, perhaps for all customers who watched more than two movies that month. Or giving customers a way to rent a combo phone/broadband Internet line for the guest room, because Uncle Bob, with the electronic toolbelt and the phone growing out of his ear, is headed in for the weekend. All the while, the new generation of transactions must know how to apply the right taxes to each service combination.
And that’s just for video and data. Adding voice services makes everything else look easy, billing aficionados say. Just adding a new telephony customer means sending alerts to the agencies of emergency/911, directory assistance, and the national databases that route calls. That’s before setting up the account for calling features, or making a way for a phone number to be returned to the local exchange carrier if a customer moves.
Suddenly, there’s lots more information that needs to be collected, from lots more equipment, in order to know what’s going on. The process of extracting the data necessary to compile a transaction is known in billing circles as “mediation.” Tactically, mediation culls the data inside the headend controllers, for broadcast video services, or from video servers, for on-demand services. Ditto for the CMTS and telephone switch, for data and phone activities.
But information is just information, without rules. That’s where rating comes to life: It establishes what rate to apply to a transaction, based on pre-established conditions. For telephony, mediation is what harvests a call detail record from the switch. Rating is what calculates the price of the call, based on time of day and rate per minute. Or, in a multiple ISP environment, mediation and rating are the enforcers of bandwidth-based contractual agreements (between the MSO and the ISP), to make sure bandwidth overages are captured.
It’s like a spreadsheet, in a way. The mediation data is what’s in the cell; the rating is the equation applied to that cell to come up with the answer.
Then, there’s settlement: the collection and remission of monies not related to consumer billing. Example: Digital interactive customers who click on an enhanced ad and request something (thus making themselves a coveted “qualified lead”) are worth something. Or: A call from Denver to Tokyo may transit eight different networks. Each hop has a cost. In both cases, something has to collect or remit money.
Billing, as it is today, is complicated. Billing, as it needs to exist tomorrow, is more complicated – just like everything else. That’s why it’s probably time to learn the rudiments of relational databases (like plastics, they’re the future, son).
It’s also probably time to warm up to those people in the computer department who come to your aid when you suddenly can’t sync your Blackberry with the office mail server. Billing systems are their life, and so the entire back office is their life. Know them and know where you’re headed.
This column originally appeared in the Broadband Week section of Multichannel News.