LNP's Gauntlet

Leonard is an avid telecommunications consumer. He favors choice. So, when wireline competition and LNP move to his town, Leonard switches from the entrenched LEC to the upstart CLEC. Leonard also uses a wireless phone to help manage his busy household's activities. Running late one evening, he tries to call home, but his call won't go through. Several tries -- nothing. Leonard is stuck in traffic and he can't reach his wife. Why? Because for any number of reasons, the LEC's LNP system fails to correctly complete Leonard's wireless call home to his (now ported) home number. Who does Leonard hold responsible? Not the LEC. Not his CLEC. He's cursing the device in his hand, and that means you.

Multiply Leonard's situation by all of your customers whose calls to ported numbers also are not getting through, and you may have a major churn problem on your hands.

Today, about 70% of wireless calls are to local wireline numbers. Even though the wireless industry gained a regulatory delay in LNP's full deployment, wireless carriers still have to complete calls to ported wireline numbers. That's where the trouble started for Leonard, for his wireless carrier and for the CLEC.

BUILD, BUY OR DEFAULT? When it comes to LNP, you have three basic choices: purchase a turnkey LNP system, outsource to a service bureau or default to the LEC. The choice is a business decision that varies from carrier to carrier and even from market to market. You must consider significant cost factors and assess market conditions. One critical element you need to examine closely, no matter which alternative you choose, is the LNP system's reliability. Consider Leonard: He wants his phone to work anywhere, anytime. He doesn't care that the number-portability administration center (NPAC) didn't send the data to the LNP service-management system (LSMS), which was supposed to update the number-portability database (NPDB), which should have provided the correct call routing to the switch. Leonard wants reliability, or in the spirit of competition, he'll walk.

Certainly, one option for wireless carriers is to default all LNP queries to the LEC, like Leonard's carrier did. However, the key to system reliability is redundancy. The more backup options you have for LNP, the more reliability you will realize. This means that you should build your own LNP infrastructure or purchase the capability as a service bureau from a trusted third party. Then, if the in-house system or the service bureau fails, queries always can default to the LEC as a backup. Of course, there are no absolute guarantees for reliability. But, by taking this approach, you protect yourself and your customers on several fronts, as opposed to banking solely on the LEC.

RELIABILITY FACTORS TO CONSIDER In theory, when you add a signal transfer point (STP), signal control point (SCP) or service switching point node in your network, you add at least four failure points: the link in, the link out, the hardware platform and the software. LNP is even more complex; it adds several new network elements, each with its own failure points.

* Links in and out: A TIA standard known by its project number, PN-3980A, also known as interim standard IS-756 defines the LNP interface between the MSC and the real-time NPDB. The standard defines a query message called the number-portability request that the MSC sends to a NPDB to obtain the location routing number associated with a ported directory number. If the number is not ported, routing information is not returned, and the (dialed) directory number is used as the routing number.

* Link to the database: The connection between the NPAC and the LSMS, defined by the North American Numbering Council (NANC) interoperability interface specifications and functional requirements specifications is another critical interface. The NPAC drives the simultaneous, real-time network element updates in a region. The NPAC and its clients communicate using a common management-information-services element (CMISE) application. Unfortunately, the NPAC communicates with its clients at higher volumes, and the additional control, routing and error-checking data associated with CMISE exacerbates CMISE's latency problems. Delays in completing consecutive broadcasts to service providers will likely increase as the number of service providers increases. Future NANC interface specification revisions will address this issue, but in the meantime, you need to be aware of this complex scenario and manage customer expectations if calls get bogged down.

* SS7 hardware and software: You must take the additional traffic that LNP creates on an SS7 network into account. It could easily overwhelm a network that is chugging along just fine otherwise.

Assume that a wireless carrier has 1 million subscribers. Each subscriber makes, on average, 2.5 calls per day, and 70% are to local wireline numbers. Assume that all of the NPA-NXXs are open for porting (an assumption that is quickly becoming a reality). The carrier will generate 1.75 million queries per day or a peak of 68 transactions per second given a 14% busy hour. This activity is over and above all the network activity already taking place, including ISUP SS7 call-connection messaging and IS-41 roaming activity.

Today's SCP solutions typically are limited to a maximum total transaction rate of under 1,000 transactions per second, based on an average query/response message size of 100 bytes with each link engineered at 40% capacity. Although 40% sounds like plenty of capacity, it includes other activity happening at the same time, such as roamer registrations and authentication. A failure to handle high-volume traffic can cause delays, time-outs or, in the worst case, incomplete calls.

To reach maximum reliability, you need a network platform that exceeds the needs of all the queries the switches throw at it. An integrated STP/SCP LNP platform is an alternative approach and a new concept in advanced IN deployment. This integrated approach can handle more than 20,000 transactions per second on a single platform that supports more than 400 SS7 links. Installing, operating and maintaining your own STP may not be feasible or desirable, but a service-bureau provider that already has this capability may be a solution.

DON'T FORGET FACILITIES Once you have established that your LNP is running on a reliable SS7 network, you should consider some LNP-specific reliability issues. Your LNP facility is at the top of the list. House your high-performance equipment so that a blackout or natural disaster cannot knock out service for any length of time.

Maximum reliability also requires regular data backups. You should automate your backup process. Additionally, you or your LNP-system provider must have and follow disaster-recovery plans, which include processes for data storage, retention and restoration. Other things, such as redundant air-conditioning systems, under-the-floor, water-detection systems and fire-detection systems, also are necessary to fend off unexpected surprises.

NUMBER CHANGES The administration of number changes is another LNP aspect that may significantly reduce network reliability. When Leonard ported his home phone number from the LEC to the CLEC, both the LEC and CLEC had to report the change in all copies of the local database. This process involves the recipient carrier sending a local service request to the donor carrier, which in turn sends a firm order confirmation. Then, both carriers need to send service-order activations to the NPAC for the port to occur. Any human, hardware or software error in this process could result in database inconsistencies and dropped calls. Critical errors can even cause an entire local calling area to be denied service.

Monitoring the platforms, computers and systems from a remote or central location can be critical to maintaining a high level of network reliability. Some of the many items involved in the system monitoring include:

* Fault detection, isolation and error recovery: Maintain procedures in hard-copy form at each monitoring station and conduct periodic training classes.

* Self-diagnostics capability: Although many parts of LNP systems have redundant backups, you must report and correct a malfunction as soon as it occurs to minimize the time when only one critical element is working. Optimally, the self-diagnostic equipment should notify the monitoring staff automatically.

* System audit: The system needs to maintain logs, including time history of all user actions, inputs, activities and alarms. Automated audits should take place between local disk storage and database, between the local service-management system and the NPDB, and for internal transaction processing diagnostics.

* Operational and service measurements: Processes should include monthly service-level reviews with communications-facilities providers and internal departments. You should review any system interruption, even those that don't affect the customer, as well as follow appropriate prevention plans to keep it from happening again. You also should review link-availability and link-usage reports.

* Capacity analysis: Your operations staff needs to look at the percent of capacity your hardware module uses for capacity-planning purposes. As a standing rule, when you reach 35% usage, you should initiate procedures for adding link-layers within a physical facility or adding facilities where necessary.

RELIABILITY & HUMAN ERROR Of all LNP elements, any part of the process that requires human data entry is risky. For example, switch updates, routing table input and application support all require human interaction and are frequent error sources. Although you never can eliminate human error, you can minimize it by starting with good hiring processes and continuous training.

Whether you view LNP implementation as a challenge or as an opportunity, the gauntlet has been thrown down. In May, the number of ported lines in the United States surpassed 2 million. This figure is climbing quickly as more CLECs open their doors.

LNP reliability will become more important as the industry moves to full wireless portability. It is likely that the LNP infrastructure will be used for number pooling to solve NPA-NXX exhaustion, which will further increase this infrastructure's performance requirements. In turn, it increases the need for reliability.

When porting begins for wireless carriers, customers will be able to churn faster and more conveniently because they will take their numbers with them. If you don't have a reliable LNP solution, and your customers' calls are not completed, your customers will leave you for your competition. If you get it right the first time, the Leonards of the world will flock to your door, seeking the reliability on which you've staked your reputation.

TTC's operational support system (OSS) offering, NetOptimize, enables pro-active quality management and streamlines problem-resolution processes with a focus on end-to-end customer-service visibility. The OSS provides one management system for many service classes with multiple underlying network technologies so carriers can bring new services to market rapidly, require less training for operations personnel and increase CSRs' responsiveness. It gives users control over private-line services and facilities ranging from DS0 through OC-48, as well as fast-packet services, including frame relay, IP and ATM.

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