Aaron's Worthless Words

Per the standard rules, please correct anything that’s wrong.

One of EIGRP’s big features is the ability to use unequal cost paths for load balancing.  This is done with the variance command.

variance : A multiplier used to calculate which feasible successors can be used as active routes.  The router takes integer and multiplies it by the successor’s feasible distance, and any FS with a an FD less than this new number gets submitted to the routing table manager.

R1(config-router)#variance ?
 <1-128>  Metric variance multiplier

maximum-paths : The maximum number of routes to submit to the route table manager.

R1(config-router)#maximum-paths ?
  <1-32>  Number of paths

traffic-share balanced : The router sends traffic based on a weighted values of the metric so that the lower metrics get more traffic.

R1(config-router)#traffic-share balanced

traffic-share min : Only use the lowest metric route.  This seems kind of pointless to me.

R1(config-router)#traffic-share min

traffic-share min across-interfaces : Use the lowest metric route but use routes out different interfaces if they exist.

R1(config-router)#traffic-share min across-interfaces

Aaron Conaway

I like to lean my head to the left, hit it with the palm of my right hand, and document what knowledge falls out.

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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.

1. Match DNIS (the dialed number) with the incoming called-address config in the dial peer
2. Match the ANI (the calling number or caller ID) with the answer-address config in the dial peer
3. Match the ANI with the destination-pattern config in the dial peer
4. Match an incoming POTS call to the port config in the dial peer
5. 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.

1. It takes whatever codec is sent to it and can't be hard-coded.
2. DTMF is sent in the audio stream, so, if you wind up with a G.729 or other highly-compressed codec, you may have problems getting DTMF across successfully.
3. IP precedence values are stripped out of the packets, so it's just plain data now.
4. RSVP is disabled.
5. No application support, so you can't do IVR.  [Will AA work?]
6. No DID support.  This means the wife can't dial your desk with your published number.

Aaron Conaway

I like to lean my head to the left, hit it with the palm of my right hand, and document what knowledge falls out.

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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

Period : Represents a single digit

destination-pattern 3…   <- matches a 4-digit number that begins with a 3
destination-pattern 91802…….   <- Matches a 12-digit number starting with 91802

Plus : Matches from 1 to 32 instances of the previous digit or pattern

destination-pattern 85+   <- matches an 8 followed by 1 to 32 5s
destination-pattern 1+  <- matches 1 to 32 instances of the digit 1

Percent or question mark :  Matches from 0 to 32 instances of the previous digit or pattern

destination-pattern 74%   <- matches a 7 followed by 0 to 32 4s
destination-pattern 84

Brackets : Matches a range or group of digits

destination-pattern [2-4]…   <- matches a 4-digit number that begins with 2, 3, or 4
destination-pattern [159]…   <- matches a 4-digit number that begins with 1, 5 or 9

Parenthesis :  Groups digits together to match with a +, ?, or %

destination-pattern (61)+   <- matches 61, 6161, 616161…up to 32 61s
destination-pattern(555)+   <- matches 555, 555555…up to 32 555s

Remember to think about digit stripping if you're using these on POTS dial peers.  The directive no digit-strip may help you out.

Aaron Conaway

I like to lean my head to the left, hit it with the palm of my right hand, and document what knowledge falls out.

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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.

Here we go.

• Telephony
  • Maximum of 10 DNs
  • Maximum of 5 ephones
  • DHCP server that provides the appropriate DHCP scope option for getting the phones online
• Phones
  • Phone 1
    • Sales Phone A
    • Button 1: extension 1001
    • Button 2: intercom to phone 3 labeled as "Lackey"
    • Pickup Group 3001
  • Phone 2
    • HR Phone A
    • Button 1: extension 1002
    • Pickup Group 3001
  • Phone 3
    • Sales Phone B
    • Button 1: extension 1003
    • Button 2:  monitor button 1 on phone 1
    • Button 3: intercom to phone 1 labeled as "Boss" that answers unmuted
    • Pickup Group 3002
• Paging
  • Each department should have its own paging group.
  • All phones should be in a paging group for broadcasting emergencies to all employees.
• Call Parking
  • 2 call parking DNs
  • 1 CP DN should be dedicated to phone 2
• Music on Hold
  • MOH should play when a user is on hold or in a park slot
• After-hours
  • After hours should be Mon – Fri from 7pm to 7am
  • No one should be able to dial 1003 after hours
  • No one should be able to dial 1002 any day at any time

I'll get my own answer together and post the consensus result in a few days.  In the meantime, let me know how terribly I did.

Send any unlicensed CIPC phones questions my way.

Aaron Conaway

I like to lean my head to the left, hit it with the palm of my right hand, and document what knowledge falls out.

More Posts - Website

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

• 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

!  Multicast Paging
!  When 1045 is dialed, ephone 2 is paged
R1(config)#ephone-dn 45
R1(config-ephone-dn)#number 1045
R1(config-ephone-dn)#paging ip 239.1.1.100 port 2000
R1(config-ephone-dn)#exit
R1(config)#ephone 2
R2(config)#paging-dn 45

!  Multiple Group Paging
!  When 1046 is dialed, both ephones 1 and 2 are dialed
R1(config)#ephone-dn 46
R1(config-ephone-dn)#number 1046
R1(config-ephone-dn)#paging group 44, 45

• There is a limit of 10 DNs in the paging group.

After-hours Call Blocking

• Allows you to configure time ranges and patterns that cannot be called during those ranges
• Three steps
  1. Defines days and/or hours that are considered after-hours
  2. Specify patterns to be blocked
  3. Create exemptions

R1(config)#telephony-service
R1(config-telephony)#after-hours day mon 18:00 07:00 <- afterhours = 6pm to 7am
R1(config-telephony)#after-hours day tue 18:00 07:00
R1(config-telephony)#after-hours day wed 18:00 07:00
R1(config-telephony)#after-hours day thu 18:00 07:00
R1(config-telephony)#after-hours day fri 18:00 07:00
…
R1(config-telephony)#after-hours date Dec 25 00:00 00:00 <- Christmas is after hours
…
R1(config-telephony)#after-hours block pattern 1 91900……. 7-24 <- Pattern index 1 blocks 900 numbers 7day/24hours
R1(config-telephony)#after-hours block pattern 2 91………. <- Pattern index 2 block all long distance after hours
…
R1(config-telephony)#login timeout 15 clear 18:00 <- Allows logins for entering a PIN for after-hours exemption; times out in 15 minutes and clears at 18:00
R1(config-telephony)#exit
R1(config)#ephone 1
R1(config-ephone)#after-hours exempt <- the boss's phone can call anywhere except the 7-24 patterns
R1(confg-ephone)#ephone 2
R1(config-ephone)#ping 1234 <- Your phone can log in with this PIN for after-hours access

• Phones have to be restarted or reset for the Login key to be enabled.

Call Accounting

• It's important to see who is calling international numbers every day at lunch.
• Call Detail Records (CDRs) record who called what number when for how long plus more stuff.
• CME logs CDRs to the logging buffer, syslog, or both.
• Logging buffers clear when a router loses power, but it may be better than nothing.  <- Don't do this ever!  Get a syslog server!

R1(config)#logging buffer 512000 <- Set the logging buffer size to 512000 bytes
R1(config)#dial-control-mib retain-timer 120 <- Roll records out in 120 minutes
R1(config)#dial-control-mib max-size 100 <- Only keep last 100 records

• Sending to syslog allows you to keep more records

R1(config)#gw-accounting syslog
R1(config)#logging 192.168.0.2 <- Log to this server

• Account codes are used for billing.
  • Each department or unit can enter a code that appears in the CDR for use later.
• Users press the Acct key when the call is ringing or connected to enter their code.

Music on Hold

• Do I have to explain what MoH is?
• WAV or AU file in flash
• Files must be G.711 or G.729
  • G.711 is recommended since it is of higher quality
• Can be delivered via unicast or multicast

R1(config-telephony)#moh piratedmusic.au <- Plays a local audio file as MoH
R1(config-telephony)#multicast moh 239.1.1.15 port 2001 <- multicast the MoH

Aaron Conaway

I like to lean my head to the left, hit it with the palm of my right hand, and document what knowledge falls out.

More Posts - Website

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

Call Forwarding

• Can be done by the user or through CLI
• User presses CFwdAll button, enters a number, and #; pressing CFwdAll again cancels forwarding.
• CLI forwarding is more flexible

R1(config-ephone-dn)#call-forward busy 1800
R1(config-ephone-dn)#call-forward noan 1800 timeout 25 <- if no answer after 25 seconds
R1(config-ephone-dn)#call-forward max-length 0 <- disabled forwarding
R1(config-ephone-dn)#call-forward max-length 4 <- restricts forwarded number to a length of 4 digits

• H.450.3: A voice gateway redirects the forward to another gateway instead of using the phone as a proxy
  • Direct path from originator to destination
  • Frees up network resources by keeping path direct
  • Keeps latency and jitter down by avoiding long looping paths and a hairpin turn at the phone
• Forwarding patterns can help restrict where calls can be forwarded

R1(config-telephony)#call-forward pattern 1… <- allows forwarding to a 4-digit number starting with 1

Call Transfer

• H.450.2: A voice gateway redirects transfers to another gateway instead of using the phone as a proxy.
  • The user doing the transfer is dropped from the conversation after transfer is complete.
• Generically, there are two types of forwarding.
  • Blind: sends the caller to the number blindly
  • Consult:  allows you to talk to the endpoint before transferring the call
• CME has three types of forwarding.
  • full-blind:  blind transfers using H.450.2 or SIP REFER
  • full-consult:  consult transfers using H.450.2 or SIP REFER if second line is available; if not, fall back to full-blind
  • local-consult:  Cisco-proprietary method for full-consult

R1(config-telephony)#transfer-system full-consult
- or -
R1(config-ephone-dn)#transfer-mode consult

• Transfer patterns work similarly to forwarding patterns

R1(config-telephony)#transfer-patter 1…

Call Park

• Call parking allows a user to retrieve a call from any phone by "parking" the call to an extension.
• The call can be picked up from any phone able to dial that extension.
• Park numbers can be assigned randomly or manually.

R1(config-ephone-dn)#park-slot <- makes this DN a park slot

• Call parking has several options.
  • reserved-for dn:  Only that DN can use this park-slot
  • timeout seconds:  Ring the phone phone that parked the call after that many seconds to remind them of the park
  • limit count:  After that many timeout intervals, drop the call.  Not good for customers.
  • notify dn [ only ]:  Notify that DN when a timeout is reached
  • recall:  Sends the call back to the original phone when the timeout is reached
  • transfer dn:  Sends the call to this DN when the timeout is reached
  • alternate dn:  If the DN in the transfer command is not available, go here
  • retry seconds:  Try to transfer again after this many seconds
• The phone must be reset for call parking to take effect.

Call Pickup

• Allows users to pick up other ringing phones
• Best to use pickup groups so the sales guys don't pick up support calls by accident

R1(config-ephone-dn)#pickup-group 5000

• There are three methods to pickup a call.
  • Directed pickup:  A user picks up a ringing phone by pressing PickUp followed by the target DN.
  • Local group pickup:  A user picks up a ringing phone in his pickup group by pressing GPickUp then *.
  • Other group pickup:  A user picks up a ringing phone in another pickup group by pressing GPickUp then the other group number.

Intercom

http://www.youtube.com/watch?v=3P2dbwrT_fQ

• Technically is a speed dial and auto-answer combination
• Intercom button is pressed, which dials a DN bound to another phone; that phone automatically answers on mute.
• The DNs involved usually (?) can't be dialed.
  • e.g., A101

R1(config)#ephone-dn 99
R1(config-ephone-dn)#number A99
R1(config-ephone-dn)#intercom A98 label "Boss"
R1(config-ephone-dn)#exit
R1(config)#ephone-dn 98
R1(config-ephone-dn)#number A98
R1(config-ephone-dn)#intercom A99 label "Lackey"
R1(config-ephone-dn)#exit
R1(config)#ephone 54
R1(config-ephone)#button 5:99
R1(config-ephone)#restart
R1(config)#ephone 73
R1(config-ephone)#button 5:98
R1(config-ephone)#restart

• Other options
  • barge-in:  Places existing calls on hold on the other end and barges n
  • no-auto-answer:  Rings instead of auto answers
  • no-mute:  Doesn't mute when auto answering.  Can you say spying?

Aaron Conaway

I like to lean my head to the left, hit it with the palm of my right hand, and document what knowledge falls out.

More Posts - Website

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

1. Phone connects to an Ethernet switch and gets power if needed
2. Switch tells the phone the correct voice VLAN through CDP
3. Phone sends DHCP request for its voice VLAN
4. DHCP offer includes the TFTP server from which to download the config
5. Phone downloads the config from the TFTP server
6. Phone contacts the call processing server as dictated in the config file

DHCP Settings on a Cisco Router or L3 Switch

R1(config)#ip dhcp pool MYPOOL
R1(dhcp-config)#network 192.168.0.0 255.255.255.0
R1(dhcp-config)#default-router 192.168.0.1
R1(dhcp-config)#dns-server 192.168.0.10
R1(dhcp-config)#option 150 ip 192.168.0.20  <– Tells the phone to download the config from this TFTP server
R1(dhcp-config)#exit
R1(config)#ip dhcp excluded-address 192.168.0.1 192.168.0.100  <– Don't use these IPs when handing out DHCP

NTP

Why should you use NTP for a CME setup?

• Phones display correct time
• Voicemails have the correct time
• CDRs are timestamped accurately
• Router logs are timestamped accurately
• Time-based access worked predictably

R1(config)#ntp server 1.1.1.1
R1(config)#clock timezone MYTZ -5  <– Sets the timezone to a zone called MYTZ that's 5 hours behind UTC

Aaron Conaway

I like to lean my head to the left, hit it with the palm of my right hand, and document what knowledge falls out.

More Posts - Website

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

An ephone-dn is a directory number that can be assigned to one or more phone.  This is usually your extension and/or DID number.

Configuration in CME:

R1(config)#ephone-dn 18   <– Again, just a tag
R1(config-ephone-dn)#number 1000  <– the extension

Ephone-dns (i.e., extensions) are assigned to ephones through the button directive under the ephone setup.  You can have more than one assignment per button command.

Configuration in CME:

R1(config)#ephone 34
R1(config-ephone)#button 1:18   <– Assigns extension 1000 (through ephone-dn 18) to button 1

The colon (:) in the button line is a separator that means that this is a normal ring phone – when someone dials that extension, your phone rings and lights up.  There are other separator characters.

Configuration in CME:

R1(config)#ephone 34
R1(config-ephone)#button 3m15  <– Monitors ephone-dn on button 3
R1(config-ephone)#button 4s82  <– Assigns ephone-dn 82 to button 4 but nothing will ring
R1(config-ephone)#button 5f31  <– Assigns ephone-dn 31 to button 5 with a triple ring

Aaron Conaway

I like to lean my head to the left, hit it with the palm of my right hand, and document what knowledge falls out.

More Posts - Website

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
  • IEEE standard for PoE from 2003
  • Defines power classes so different devices can ask for different power levels
    • Class 0:  15.4W allocated
      • Used for el cheapo devices that just want power
    • Class 1:  4.0W
    • Class 2:  7.0W
    • Class 3:  15.4W
  • Uses all 4 pairs of wire, so works on gig links
  • Power procedure

  1. Small DC current is applied to the line
  2. If an 802.3af device is attached, it runs the current through a resistor
  3. The resistance is detected by the switch which can determine the class of power
  4. Power is applied to the device

• Cisco Inline Power
  • Cisco's version of PoE created in 2000 (before 802.3af)
  • Each device tells the switch what its power needs are
  • Power procedure

  1. PoE device connected to the switch
  2. Switch sends Fast Link Pulse (FLP)
  3. If FLP is received back, 6.3W of power are applied
  4. Device boots off of 6.3W and tells the switch what its real power requirements are via CDP

Aaron Conaway

I like to lean my head to the left, hit it with the palm of my right hand, and document what knowledge falls out.

More Posts - Website