3 Varieties of VOIP service offered by cable operators

1. Carrier grade (Platinum standard of telephone service)
   
   • Highly reliable
   • Grow as customers are added
   • Feature rich
   • Maintainable without service outage
   • Ability to track and measure key performance indicators
2. Second tier
   • Provides "best effort" service with no guarantees of voice quality
     
   • Active from of high speed data service, that provides a 10 digit VOIP phone #
     
   • Requires an adapter to connect to the network
     
   • Vonage.com and i2Telecom.com
     
3. Third tier
   • Heavily dependant on downloaded software in user's PC
     
   • Usually Doesn't interface with a standard telephone
     
   • Usually offer call completion only between other users of the same service

To Guarantee QoS

• VOIP packets must travel from end to end in less than 150 msec
  
• Waiting time required by one packet cannot deviate by more than a given amount from the waiting time taken by any other packet
• These parameters are called delay and jitter

  3 Sub Networks that comprise a Packetcable network

1. The HFC access network
   
   1. Must be DOCSIS 1.1 or 2.0 compliant
      
   2. DOCSIS compliant HFC network includes
      
      1. Cable modems
         
         1. Provide services as
            
            1. Modulation/demodulation
               
            2. Data transmission using DOCSIS protocol
               
            3. Classification of traffic
      2. MTAs
         1. Connect telephones and computers to cable operators network, at customers location
      3. EMTAs
         
         1. An MTA that also includes a cable modem
            
         2. Available as both indoor and outdoor models
            
      4. CMTS
         
         1. Workhorse of DOCSIS access network
            
         2. Found in hub or headend
            
         3. Provide modulation and demodulation
            
         4. Ensure sufficient bandwidth for high quality telephone conversations
            
2. A managed internet
   
   1. Includes data switches and routers needed to transport IP packets and other components
      
   2. Includes gateways, that connect calls to the PSTN as necessary, and various servers that provide features billing and support
3. PTSN
   
   1. Telephone company's network
      
   2. Includes switches, transmission media, cross connections used to complete calls

  VOIP INSTALLATION

• If neither phone nor data services work
  1. 1.Check power connections
     
  2. Check cable connections
     
  3. Press reset on back of MTA
     
• If phone works but no data: press standby button until the cable and online LEDs are both on
  
• If phone is out but data is working
  1. Verify that 'tel' LED is lit
     
  2. Check for no off the hook phones
     
  3. Check battery status if able
     
  4. Check phone cables
     
  5. Disconnect fax/answering machines and check line with known good phone
     
  6. Press reset button on back of telephony modem
        The only provisioning problem that can be troubleshot in the field is verification of customer info
• Most power related problems are caused by
  1. Out of range voltage at the tap
     
  2. Faulty power cable or coax
     
  3. Misaligned power jumpers in MTA

  VOIP and the Home Security System

• Types of HSS
  • Bells only
    
  • Monitored alarms
• Both are available as either hard-wired or wireless
  
• Unmonitored systems are not affected by VOIP
  
• Response actions to an alarm
  1. Call customer to verify false alarm or not
     
  2. Notifying the police
     
  3. Notifying fire and/or rescue
• Carrier grade VOIP should work with alarm companies
  
• 2^nd and 3^rd tier might require additional equipment
  
• 3 Alarm monitoring concerns
  1. Incompatibility issues w/ the in-line seizure module
     • In-line seizure module:  A relay device that is designed to take control or seize the customer's phone line when an alarm is activated. This relay is part of the DACT (Digital Alarm Communicator Transmitter)
  2. Loss of electric power
     • PTSN is powered by phone company is event of an outage
       
     • Without battery backup, VOIP may be in trouble
  3. Problems caused by improper wiring at installation
     • Disconnect errors can occur if improperly trained
• To ensure integrity of home security system
  1. Understand the purpose of the RJ31X and locate it and the control panel
     • RJ31X is an 8-pin jack used in security systems
     • RJ31X is a passive device that is wired between an alarm panel and premise wiring to create the appropriate interface, enabling line seizures and outbound calling
  2. Verify the integrity of system by following pre-installation checklist
     
  3. Have customer call alarm company for a test and put alarm in standby mode
     • Because of the presence of a 2^nd or 3^rd ties provider it is important to have the customer precall alarm company
       
     • Perform alarm pretest
       
     • Request alarm to be put in service mode
       • The purpose of removing the RJ31X and putting in S mode
         1. To alert security system that VOIP is being installed
            
         2. To test system after installation is complete
  4. Verify that all existing phone lines are active before disconnection
• An active POTS can damage an MTA with 150 VAC during the reception of a call, disconnection of Telco service can prevent this and electrical shock.
  
• Alarm panel jumper to RJ31X uses a proprietary (private, exclusive) wiring scheme
  • Brown (tip to house wire)
    
  • Gray (ring to house wire)
    
  • Green (tip )
    
  • Red (ring from Telco or MTA)
• A typical RJ31X uses 4 wires
  • 2 for the connection to the telephone line from the MTA (T & R)
    
  • 2 for connecting the inside telephone lines (T1 and R1)
• For proper wiring of RJ31X
  • MTA tip and ring to be terminated to green and red terminals of RJ31X jack
    
  • Premise wiring must be terminated to brown (tip) and gray (ring) terminals of RJ31X jack
  
   DO NOT USE PARALLEL OR REVERSE WIRING METHODS WITH A RJ31X JACK, THIS WILL PREVENT COMMUNICATION W/CENTRAL STATION
  
  
• 3 placement options for an MTA
  1. Near the NID or RJ31X jack
     • Place here whenever possible
       
     • Advantage is a short telephone wire run
  2. 2.Run a dedicated phone line from MTA to RJ31X or NID
     • Ensure security system is first extension on the line
  3. Use a spare pair to feed RJ31X from MTA
     

  COMMON DEVICES

• CODEC is a device built into equipment that encodes or decodes a signal
• Common devices that might not work with VOIP
  1. Fax machines
  2. Medical alert consoles
  3. POS (point of sale) devices
  4. Teletypewriters
• 2^nd and 3^rd tier common device solutions
  1. Disable bandwidth saver function and set bandwidth to maximum allowed
  2. Disable call waiting
  3. Adjust the data transmission speed of the ATA
• 3 ways to initiate and receive a telephone call
  1. Initiated from and received by a PSTN customer
  2. Initiated by an alternative carrier customer and received by a PSTN customer
  3. Initiated by a broadband digital cable phone customer and received by a broadband digital cable phone customer

  THE NID

• The NID
  1. Connects customer inside wiring to PSTN
     
  2. Is bonded to common ground
     
  3. Provides test points
     
  4. Has 2 compartments
  • Craft access compartment. Craft access:   An access area available to service people exclusively
    • Contains service wire connections and cross wire connections
      
    • Grounding connections
      
    • Protectors
      
    • Electronics for remote testing
  • Customer access compartment
    • Contains a telephone jack
      
    • Plug system
      
    • Wiring bridge modules w/ screw down posts: A wire connection sometimes called a binding post that uses a screw to secure together the stripped insulated ends of several wires, or to attach stripped wires to a device
• Telephones companies utilize
  • -48 V DC
    
  • Up to 32 mA to operate phones
    
  • 130 VAC to activate ringer
• UTP (Unshielded Twisted Pair) Cable Categories
  • CM     =      General purpose, indoor cable, no UV protection
    
  • ;CMX     =      Indoor and outdoor, UV protection
    
  • CMR     =      Riser rated cable
    
  • CMP     =      Plenum rated cable
• Crosstalk is reduced by
  • Twists
    
  • Cable lay
    
  • Shielding
    
  • Physical separation
• Cat-3
  • Most common for voice grade UTP cable
    
  • Contains 5 to 7 twists per foot
    
  • Usually a 4 pair UTP
• Tip and ring
  • Ring is negative side of -48 DVC
    
  • Tip is positive side
  • Screw down jacks, not made for Cat-3 electrical specs
    
  • USOC specifics
    1. Pair 1 (white/blue and blue ) is always terminated on the center 2 pins
       
    2. Pair 2 (white/orange and orange ) is split and terminated on each side of pair 1
       
    3. Pair 3 (white/green and green ) is split and terminated on each side of pair 2
  • Tip = predominantly white
    
  • Ring = Solid color

  4 MAIN TOPOGRAPHIES

1. Star
   • Also known as home run
2. Ring
   • Like but not identical to loop through
3. Bus
   • Similar to loop through
4. Also is the Hybrid, which is a mix of 2 or more topologies

  CABLES

• Grade-1 cable standards (CAT-3)
  1. Provides minimum requirements for telephone systems
     
  2. Consists of a 4-pair UTP cable
     
  3. Using CAT-5 is highly recommended over CAT-3
• Grade-2 cable standards (CAT-5)
  1. Provides minimum requirements for telephone systems
     
  2. Consists of 2 4-pair UTP cable
     
  3. Standard applies to new construction, additions or remodels
• CAT-5 UTP
  1. High performance
     
  2. Data grade
     
  3. Twisted pair cabling
     
  4. Wound counter clockwise 12-14 twists peer foot
     
  5. Supports 100 MHz transmission speed
     
  6. High grade can sustain 155-350 Mhz trans speed
• Pair number vs. pin number
  1. Pair number is used for reference
     
  2. Pin umbers indicate actual physical locations on the modular data plug and jack or port
     
  3. Always wore both plug ends using the same wiring configuration
     
  4. Jack should be installed with the contact pins up and the locking tab down
     
  5. When viewed from front, pin numbers run from left to right from 1-8

  TROUBLESHOOTING

• Most common problems in customer premise
  1. 1. No dial tone
     • Most common problem
       
     • Usually related to network problems
       
     • Likely CP cause is another phone in house off hook
       
     • Dead batteries in phones will also cause problem
       
     • Cable faults are another cause
       • Short: In wiring, an unintended circuit path that permits current to flow to unintended places, thus impairing the normal operations of the circuit
         
       • open:In wiring, an electrical path that is not connected. It can be caused by an extremely loose or broken, or disconnected wire in an electrical path
         
       • Ground Fault: When a hot or power carrying conductor makes contact with an unintended item of/at ground/potential, a ground fault current will flow from the hot conductor through unintended components of a circuit.
  2. Continuous dial tone
     • DTMF: Dual Tone Multi-Frequency-a technique of dialing a telephone where each number pressed sends out two tones from a matrix of frequencies; synonymous with touch-tone or push button phones.
       
     • Verify that problem is at all phone jacks
  3. Noise on the line
     • More difficult to locate and repair
       
     • Types
       • Static
         • Crackling sound
           
         • Loose/corroded fittings
           
         • Poorly installed jacks
           
         • Broken wires
           
         • Defective CPE
       • Hum
         • Low continuous murmur, bee sound
           
         • Grounding/shielding problems
           
         • Poor terminations
           
         • Poor grounding and bonding connections
       • Crosstalk
         • Party line
           
         • Poorly installed jacks
           
         • Poor terminations
           
         • Deterioration or corrosion of wires
           
         • Cordless phones
       • Radio interference
         • Line is acting like a receiver/antenna
           
         • AM radio can be a cause
           
         • Ground problems
           
         • Corroded or poor connections
           
         • Poor terminations
  4. CPE ringer problems
     • Ringer switch in wrong position
       
     • A defective ringer in CPE
       
     • Improper polarity of the tip and ring
       
     • Excessive REN total
• Causes of Opens
  • Corroded or damaged IW
  • Carelessness in termination of tip and ring to wrong terminal screw
  • Loose connections at IDC (punch down) or terminal screws
• Causes of Shorts/Crosses
  • A staple, screw, etc penetrating the cable
  • Shorted tip or ring at modular jack
  • Excessive stripping of wiring during install
  • A defective CPE
  • A damaged line cord
• Reversal is when a pair of wires on a telephone line is reversed, causing a reverse polarity at the modular connector and thus the CPE
• Reversals are major causes of continuous dial tone
• Split Pairs Troubleshooting
  • A split pair is when one wire of one pair is connected to the location of another wire, ie the tip of pair one is in the spot of the tip of pair two
    • Split Pairs will cause
      • NDT
      • CDT
      • Ringer problems
• Transpositions Troubleshooting
  • Transpositions are when entire pairs of wire are terminated where another pair should be
• Common Fault troubleshooting
  • Common Faults usually occur during
    • The initial; installation process
    • A system modification
    • A retrofit procedure
    • Changes and additions to the CPE

  REMEMBER

• Any short will disable the entire system
• Any open will disable that portion of the system beyond the wire break
• A short in any CPE will disable the entire system
• An open in any CPE will cause it individually to be inoperative
• With the NIU disconnected and the CPEs unhook check customer side of IW for crosses, shorts, etc with VOM
• A system without faults will read open or Infinite Ω (OL)

  TOOLS