Introduction To Cable Modem And Personal Computer Troubleshooting
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Introduction To Cable Modem And Personal Computer Troubleshooting
Article Introduction
The article introduces the process of troubleshooting high-speed data services using cable modems. It gives an analysis of personal computer and cable modem troubleshooting techniques and discusses the need for various tools of the trade.

Article Description
Cable modem and personal computer troubleshooting is an area that often remains unattended. It is a hidden action item in a long list of things each broadband operator worries about when launching their Internet information service (also known as High-Speed Data or HSD). However, not long after launching HSD, this area becomes considerably more important and its absence in previous system design decisions delay the efforts to provide these facilities post launch. Cable modem and personal computer troubleshooting consist of the following items:
- Problem Solving
- Escalation
Through proper implementation of these items, customer problems can be resolved quickly and in a manner that optimizes the use of ones subscriber management system (SMS), technical support staff, and an application called a troubleshooting tool.

Problem Solving
Problem solving is an interactive task. During this interaction, the customer is identified and the source of the problem is determined. Depending on the broadband operator, initial contact with the customer, problem discovery, and the actual problem resolution may involve several support personnel (and/or third parties) and may span a period of minutes to days depending on the type of problem encountered. Regardless of who is involved in the problem solving, the process of problem solving is relatively the same. Figure 1.0 describes a typical cable modem and personal computer troubleshooting process. Through this process a majority of the problems associated with cable modems and personal computers can be identified and corrected - most of them during the initial dialogue with the customer.

This process starts with a short discovery period where the customer is identified, account accessed, the problem is stated, and the trouble ticket is opened. If the problem is of technical nature broadband service representatives (BSR) follow the process in Figure 1.0 beginning with "Start" until such time as they have either identified and corrected the problem or escalates the problem to another person to further troubleshoot and/or correct the problem. The key to this technical process is to correct all common sense type problems or those problems that can be easily corrected over the phone. This technical process is "in addition to" any standard BSR script. For example, most BSR scripts might first ask customers if their cable television reception is ok or has the customer changed any wiring in their home. If the customer passes these checks the BSR then guides them through the cable modem and personal computer troubleshooting process.

A troubleshooting tool provides BSRs with critical information that allows them to dissect the customers problem. Since the cable modem precedes the personal computer (connectivity wise) it serves as a good place to break down the problem. Here the goal is to divide the problem in half and continue to divide the problem until the source of the problem is found. Typical problems associated with cable modems include:
- Wiring - bad initial install wiring, customer altered, or damaged
- Connectors - poorly secured, customer altered, or damaged
- Signal - too hot, not enough, filtered, ingress
- Provisioning - Removed by mistake, customer exchanged
- Hardware - device failure

The troubleshooting process usually begins by pinging the cable modem. If the cable modem cannot be pinged, the troubleshooting process focuses on probable causes (i.e. unplugged AC/RF). Any causes that are corrected (e.g. AC was reconnected) require the BSR to re-attempt a ping to the cable modem. If cable modem remains un-pingable, problem solving turns from connectivity to provisioning. Here the cable modems Media Access Control (MAC) address is verified with the customer and with the troubleshooting tool. If the MAC address is not provisioned or incorrectly provisioned (typo) this is corrected. If connection is intermittent or performance is noticeably slow, all connections should be checked first and confirmed snug before proceeding with checks for signal level. Checks for signal level involve using the troubleshooting tools get-health* function. This reads the cable modems current transmit and receive power levels which can be compared with the cable modems levels at the time of installation. If the newly acquired levels fall out of normal range or vary greatly from those at the time of the install the trouble ticket is escalated to field operations for a service appointment.

The success or failures of this step leads to either a verification that the problem is fixed or a service appointment to ensure proper signal levels and/or replace the cable modem. If the customer is not leasing the cable modem (i.e. purchased it retail), the service call may be as simple as a check for services after which point the problem is corrected or the customer is referred back to the retailer who sold them the cable modem.

Following a successful ping and get-health of the cable modem, the troubleshooting process next focuses on the personal computer. Typical problems associated with personal computer include:
- Wiring - bad initial install wiring, customer altered, or damaged
· Connectors - poorly secured, customer altered, or damaged
· Configuration - incorrect or missing
· Operating System - unsupported version, defective, or missing proper drivers
· Applications - unsupported
· Hardware - device failure or needs re-seating

A successful ping and get-health to the cable modem leads to a ping of the customers personal computer. If the personal computer is not pingable, the connections between the cable modem and customer computer are checked. The easiest way to do this is to look for link (or transceiver) status light on each end of this connection. Most personal computer network interface cards (NIC) and cable modems have these link lights for troubleshooting - it is strongly recommended that only NICs that have these link lights be used. If there is no link light the problem is a bad connection, damaged wire, or a failed device. Check the wire between these devices and also check connectors/connections. If the wire or connections are damaged, the customer can be referred to a customer service site to pick up a free replacement. If both look ok its likely one of the devices has failed and this trouble ticket would should be escalated to field services for a service appointment.

If there is good connectivity between the customers personal computer and the cable modem, the personal computers MAC address is verified. If the MAC address is not verified (i.e. customer changed their personal computer or NIC), their old MAC must be deprovisioned and the new MAC address provisioned. The BSR then uses the troubleshooting tool to ensure the MAC is provisioned. If the troubleshooting tool indicates the MAC address is not provisioned, the MAC is reprovisioned until it shows up as provisioned. Once provisioned, the customer is then asked to reboot their personal computer to attempt to acquire a new IP address. If the personal computer obtains an IP address, which is visible in the computers network settings, the troubleshooting tool should be able to ping it. If at that point the personal computer cannot be pinged, the network settings must be verified. The use of Dynamic Host Configuration Protocol (DHCP) for personal computers speeds the settings of proper network configurations - in fact most operating systems today default to DHCP when installed.

If network settings are correct, the next thing to check might be the drivers which are required on some computers. However, at this point one has done just about as much as one could expect to do over the phone. Verifying drivers gets messy and can lead to causing more problems - especially on computers with multiple NICs and/or expansion cards. Proceeding from here is based on you and your customers tolerance for lengthy phone conversations. At an estimated $1.20 per minute, a lengthy troubleshooting call can cost as much if not more than a results oriented troubleshooting call combined with a service appointment - the latter of which usually ends with a satisfied customer. That does not include the time the customer spent on the phone traversing Interactive Voice Response (IVR) menus or the time they spent waiting on-hold to talk to a BSR.

Balancing ones toleration for phone conversations with truck rolls or further routing is the key to establishing proper escalation. All escalations follow a process similar to that described in Figure 1.1. The escalation process is divided into tiers, each of which is responsible for an increasingly more particular level of support. For example, a BSR (Tier 1) will handle any conversation with customers regarding general problems where as a Plant Operations technician (Tier 4) would only deal with specific plant issues and seldom (if ever) talks with a customer directly.
Posted : 10/26/2005

Introduction To Cable Modem And Personal Computer Troubleshooting