Iiuc on Aaron's Worthless Words

IIUC Update - Passed!

Wed, 09 Feb 2011 00:00:00 +0000

I passed the IIUC yesterday, so now I’m a CCNA Voice. It’s kind of belittling to get a CCNA-level certification at this point in my career, but I didn’t want to be completely left behind, so I figured I should move into some voice stuff before I’m left in the dust.

The exam was probably the best Cisco exam I’ve ever taken. Of all the exams I’ve taken in the last few years, this is the only one that didn’t have questions with huge misspellings or grammatical errors. I was really taken aback at that since a good portion of the questions from some of my recent CCNP exams were plain unreadable. I think I remember leaving a comment on one IIUC question about the word “an” being left out of a description, but that was no big deal. I’m not that obesessive-compulsive.

IIUC Notes - Inbound Dial Peer Matching

Wed, 19 Jan 2011 00:00:00 +0000

More IIUC notes. As always, feel free to correct as needed.

To match inbound calls to a dial peer, CME (and CUCM?) uses the following steps.

Match DNIS (the dialed number) with the incoming called-address config in the dial peer
Match the ANI (the calling number or caller ID) with the answer-address config in the dial peer
Match the ANI with the destination-pattern config in the dial peer
Match an incoming POTS call to the port config in the dial peer
Match dial peer 0

Matching dial peer 0 is bad, and it took me an inquiry on Twitter and a buddy to realize why. Here are a few highlights as to why. I believe the full scope of the badness of dial peer 0 is really beyond the IIUC exam.

IIUC Notes - Wildcards for Destination Patterns

Tue, 18 Jan 2011 00:00:00 +0000

As always, feel free to correct anything that needs correcting or add anything that needs adding. There is a lot more to the full definition of wildcards, but these are the basics. Note to *nix guys: This isn’t regex as you understand it. Yes, the use of curly braces would be nice, but we don’t get that here.

T: Represents anywhere from 0 to 32 digits

destination-patter 9T <- matches a 9 followed by 0 - 32 other digits

CME Exercise #1

Thu, 07 Oct 2010 00:00:00 +0000

I tried something like this earlier this year with STP. It got rave reviews (from my mother), so I figured I try it again.

Below is a list of requirements for configuring a router as a call processor. In a lab or in your head, configure the router to support the features as listed. This isn’t a contest or anything like that. If you get it right, a virtual thumbs up is all I can afford to give you. There are some licensing issues for running this stuff in GNS3/dynamips, so I can’t help you out on that. I’ll just hint that GNS3 and dynamips will bind to real networks and that copies of a compatible IP softphone are available.

IIUC Notes - Voice Ports and Dial Peers

Mon, 04 Oct 2010 00:00:00 +0000

More of my IIUC study notes. As always, feel free to correct. I really need to have a real post, don’t I?

show voice port summary

Shows the voice ports available for use

R1#show voice port summary
                                          IN       OUT
PORT           CH   SIG-TYPE   ADMIN OPER STATUS   STATUS   EC
============== == ============ ===== ==== ======== ======== ==
50/0/1         1      efxs     up    up   on-hook  idle     y
50/0/1         2      efxs     up    up   on-hook  idle     y
50/0/2         1      efxs     up    up   on-hook  idle     y
50/0/2         2      efxs     up    up   on-hook  idle     y
50/0/3         1      efxs     up    up   on-hook  idle     y
50/0/4         1      efxs     up    up   on-hook  idle     y
50/0/5         1      efxs     up    up   on-hook  idle     y

An ephone-dn shows up as efxs, so all these are ephone-dns.
Channels are numbered 0-23; timeslots are numbered 1-24

FXS Ports

IIUC Notes - More Phone Features

Sat, 02 Oct 2010 00:00:00 +0000

Here are some more notes from my IIUC studies. As always, corrections requested.

Paging

Broadcasts messages to a group for a one-way communication
Paging groups are used to limit which phones get the broadcast
Paging can be unicast or multicast
- Unicast groups limited to 10 members
- Multicast requires mcast support on the network
Paging configurations can be unicast, multicast, or multiple-group

! Unicast Paging
! When 1044 is dialed, ephone 1 is paged
R1(config)#ephone-dn 44
R1(config-ephone-dn)#number 1044
R1(config-ephone-dn)#paging
R1(config-ephone-dn)#exit
R1(config)#ephone 1
R1(config-ephone)#paging-dn 44

IIUC Notes - Phone Features

Fri, 01 Oct 2010 00:00:00 +0000

Here are some more notes from my IIUC studies. As always, corrections requested.

Local Directory

Allows users to look up names
Allows names to show up when dialing or receiving a call
Most phones have a directory button; some have a menu options for the directory

R1(config)#ephone-dn 1
R1(config-ephone-dn)#name Roger Smith

Directory entries can be added manually

R1(config-telephony)#directory entry 1 1700 Corporate Fax
R1(config-telephony)#directory entry 2 1701 HR Fax

By default, sorting is done alphabetically by first name.
Sorting can be changed

R1(config-telephony)#directory last-name-first

IIUC Notes - Getting Phones on the LAN

Thu, 30 Sep 2010 00:00:00 +0000

More study notes. Correct if wrong, though I hope I get some of it right since I already since I’m an R&S guy. :$

**Switchport Configuration
**

switchport mode access: This config makes the port an access port that carries the primary and voice VLAN traffic
switchport mode trunk: This config akes the port a trunk unconditionally, but it will still send DTP messages
switchport nonegotiate: This config keeps the port from sending DTP messages.
switchport mode dynamic auto: If the port receives DTP messages, it will become a trunk. If not, it will be an access port.
switchport mode dynamic desirable: The port actively sends DTP messages trying to become a trunk. This is the default configuration on a Cisco switch.

Cisco IP Phone Boot Process

IIUC Notes - Assigning Ephone-dns to Ephone Buttons

Thu, 23 Sep 2010 00:00:00 +0000

These are some of my notes on my IIUC studies. Since I am a novice as voice stuff, please let me know what I get wrong.

An ephone is a representation of a phone. It’s basically a structure of features that a phone will have.

Configuration in CME:

R1(config)#ephone 34 <– This is just a tag and has nothing to do with an extension or phone
R1(config-ephone)#mac-address 1111.2222.3333 <– Assigns this ephone to the phone with that MAC address

IIUC Notes - Powering Cisco Phones

Tue, 21 Sep 2010 00:00:00 +0000

Feel free to correct anything that is wrong or incomplete.

Power over Ethernet (PoE)
- Can provide power to a Cisco phone, access point, security camera, etc., through the network cabling, eliminating the need to plug the phone into the wall for power.
- Generic term for providing power on the Ethernet cable
- Provides centralized power that can be put on a UPS
- Allows devices to be located away from power outlets
- Removes cabling clutter at the user’s desk
- Can be provided through PoE-enabled switches, power panels or inline couplers (power injectors)
- Oversubscription is common
  - If every device on a switch asks for full power, the switch may not be able to handle the load.
- Of course, devices can be powered with a power brick at the desk
802.3af

IIUC Notes - VoIP Structures

Tue, 21 Sep 2010 00:00:00 +0000

Feel free to correct. No need to sugar-coat it; I’m pretty new at this stuff. :)

Advantages of VoIP
- Reduces costs of communications: Eliminates/reduces long distance and international call tolls
- Reduces costs of cabling: No need for second network of phone lines
- Integrates all voice into one large network: All your remote offices can be implemented/maintained/controlled centrally
- Provides mobility: Moves, adds, and changes (MACs) are (nearly) eliminated since your phone is just a network node
- Allows use of IP Softphones
- Unifies emails, voice mails, and faxes: All these can be treated as a single box for user messages
- Increases productivity: Ringing multiple devices at the same time eliminates phone tag. <— pushing it, eh?
- Enhances communications: Applications can be launched/updated from a voice call through application servers
- Provides open, compatible standards: You can connect different vendor devices into the same VoIP network. <— I’ve never seen that happen
Cisco VoIP Structure

IIUC Notes - Old School Voice Stuff

Wed, 08 Sep 2010 00:00:00 +0000

These are the notes I’ve taken as I read through the study materials. Feel free to correct anything you see.

Analog phone signaling
- Misc
  - Ground = positive = tip
  - Battery = negative = ring
  - Signaling uses specific frequencies for specific events
- Loop start signaling
  - When a circuit in the phone is completed (i.e., you take it off-hook), the CO detects it and provides services.
  - Susceptible to glare, where the phone requests dialtone at the same time that the CO sends a call.
    - Can connect two different calls if in a business with multiple lines
- Ground start signaling
  - The circuit is temporarily completed to signal the CO for services
  - Doesn’t connect any call to any phone directly
  - Used in PBXes.
- Supervisory signaling
  - On-hook: Circuit is open
  - Off-hook: Circuit is completed
  - Ringing: AC current generated by CO to tell the phone to ring
- Informational signaling
  - Gives information for the caller to use
  - Dial tone
  - Busy
  - Ringback: the ring you hear when you call
  - Confirmation: the call is being attempted
  - Congestion: no lines available to make the call
  - Receiver off-hook
  - Reorder: can’t make the call
  - No such number: can’t find the endpoint
- Address signaling
  - Used to send digits
  - Dual-tone multifrequency (DTMF): uses two electrical signals to indicate a digit; touch tone
  - Pulse: flashes the circuit to indicate a digit; rotary dial
- Disadvantages of analog signaling
  - Attenuation
  - Repeaters can’t differentiate between call and noise
  - One cable pair for each call; think about a pair for each call taking place in Manhattan right now
Digitizing voice