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Carrier Services
MWC 09: Telstra gets to the core of matters
Ongoing core network transformation supports IP services and wireless backhaul
by Sean Buckley
Australia-based incumbent service provider Telstra’s core and edge network transformation reads like a textbook example of how telco networks have been built to accommodate data services; that is, consisting of a collection of diverse overlays — one for ATM, another for Ethernet, one for IP, and of course one for Frame Relay.
Making the transformation even more challenging, Telstra has also been aggressively rolling out a national 3G wireless HSDPA data network that reaches 99 percent of Australia’s population.
In 2005, Telstra decided that such a configuration would not optimally scale as it requires the obvious maintenance of multiple networks. This new backhaul network would be able to accommodate both its wireless and wireline networks.
“One of the things we made a decision to do both in the wireline and the wireless space is make sure we had the right backhaul environment to facilitate the future,” explained Michael Lawrey, Executive Director of Operations for Telstra. “And the backhaul is literally the backbone because if that’s not right nothing else works.”
Future proofing
By having one converged network, Telstra can deliver any type of service whether it’s fixed line, mobile or cable.
To develop the right core backhaul plan, Telstra employed the help of Alcatel-Lucent as a lead network integrator to design a common Ethernet core backhaul network.
With Alcatel-Lucent as the lead integrator, a process that incorporated both Alcatel and Tellabs network gear, Telstra has been able to eliminate multiple network elements and have one common MPLS network to accommodate any traffic type.
Telstra now has an Ethernet backhaul network with regional and metropolitan Ethernet aggregation points (86 in total) that reaches throughout Australia. From there, Telstra connects the points via DWDM transmission gear. Then, it leverages Tellabs’ 8800 Multi Service Routers (MSRs) to provide connectivity to the customers through Ethernet, ATM or Frame Relay.
The benefit with this transition is that “we can make it as transparent for our Frame and ATM customers to migrate off our legacy environment to IP without having to change their CPE,” Lawrey said.
But this network transformation is not just about meeting current needs, but also about future-proofing for tomorrow's needs.
By deploying Alcatel-Lucent’s 7450 Ethernet Service Switch (ESS), all of which have 400 Gbps backplanes at the Ethernet aggregation points, Telstra thinks it won’t have to do any major augmentations for at least five years.
Similarly, in the network core, it has an abundance of capacity through the Cisco CRS-1 with 92 Tbps capabilities.
“We built it out for a very large scale network deployment and throughput because we want to leverage the content delivery and speed that we’re pushing either in the wireless environment or through the DSL environment,” Lawrey said.
Backhaul bonanza
Prior to beginning its core transformation, Telstra’s backhaul capabilities for both wireline and even wireless communications were all on TDM and later ATM-based links.
In particular, the operator was leveraging 2 Mbps E1 links for its wireless backhaul network.
However, Telstra soon found out as began building its 3G Next G wireless network deployment it would need multiple TDM circuits for wireless backhaul.
The operator has been quite aggressive with 3G wireless. Initially launched at 3.6 Mbps capabilities, Telstra quickly surpassed that by quickly going to 14.4 Mbps.
At the end of last year, it started an initiative to provide 21 Mbps download speeds initially in metro areas followed by regional areas starting this month.
“Once we went to 3G wireless, we found that in some cases we needed not one, not two, [but] 12, 14 and 16 E1 links to get appropriate backhaul,” Lawrey said.
Telstra’s wireless backhaul will now grow even further.
During this year’s Mobile World Congress event in Barcelona, Spain, company President and CEO Sol Sol Trujillo, said that the operator plans to increase the speeds on its HSDPA network from 21 Mbps to 42 Mbps by the end of 2009.
With the ongoing migration to a core Gigabit Ethernet network, Lawrey is confident they’ll have more than enough capacity to serve any underlying wireless and even wireline backhaul needs.
Similarly, Telstra sees an emerging trend taking place in backhauling its wireline DSLAM traffic. Along with enabling the delivery of new services, while migrating off of legacy ATM, the core network will serve yet another purpose: backhauling DSLAM broadband wireline service and wireless Internet.
To date, Telstra has transitioned about two million lines across to next-gen Alcatel-Lucent ISAM units to the next-gen network. Additionally, the operator is going to upgrade some of its legacy DSLAMs with GigE network connectivity that will also be ported onto the new backhaul core network.
What this means is the packet-based network data will run over two GigEs.
“The fundamental TDM technology of delivering on a 2 Mbps stream basis no longer meets the needs in a next-generation world so you need to move to Gigabit Ethernet connectivity,” he said. “That’s the paradigm shift Telstra has made in building out this network in that we believe the future is Gigabit Ethernet so therefore we will build out a packet data core based on Ethernet aggregation.”
Broadband battles
Even with its strong wireless and wireline broadband core built out, Telstra’s broadband drive is not without its setbacks.
One of its biggest battles is not necessarily technical, but regulatory. At issue is the Australian government’s plan for an operator to build out a national broadband network under its National Broadband Network (NBN) plan.
Under the NBN plan, the Australian government will basically award one service provider a network contract to extend Fiber-to-the-Node (FTTN) services to 98 percent of the Australian population.
Lawrey said that Telstra, which owns the copper access network, has on a telephone exchange basis, has deployed 1.5 million lines onto ISAM DSLAMs. Other than installing a couple trial cabinets, Telstra has not made a mass deployment of Alcatel-Lucent ISAMs for FTTN.
“We got the core network done, and have been ready to go for some time,” he said. “We need to work through this regulatory mire that’s been put in place, and hopefully common sense will prevail because I can’t imagine anyone else to roll a FTTN deployment nationwide as per the government requirement other than Telstra.”
To say the Australian broadband market is competitive would be an understatement. Telstra faces fierce competition from not only insurgent carriers AAPT of Telecom New Zealand and SingTel Optus, but also U.S.-based carriers such as Verizon Business.
Not surprisingly, Telstra believes it is the best equipped provider to run the NBN network and is far ahead of the bevy of competitors such as SingTel Optus in terms of building out fixed line broadband.
Lawrey thinks that competitors aren’t really as dedicated to really making a real investment in deploying broadband access.
“Even if I look at the fixed environment, the regulator ULL costs, the regulator has specified ULL below cost price, so they [SingTel Optus] gets a free leg up,” Lawrey said. “Even with that free leg up, we’ve deployed ADSL2+ out to 2,840 telephone exchanges, and they have deployed to only 350.”
Unfortunately, the outcome of Telstra’s NBN bid was not successful as the government turned down Telstra’s proposal last December.
According to various media reports, the Australian government rejected the incumbent’s bid because Telstra did not provide a provision for SMBs.
The government’s move is not exactly stopping Telstra from expanding its broadband ambitions. While Telstra has not launched a formal rebid yet it plans to continue expanding its Next G wireless network, copper (both ADSL and ADSL2+), as well as Hybrid Fiber Coax cable networks.
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