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.

ONT Notes - QoS On Wireless Networks

Thu, 11 Feb 2010 00:00:00 +0000

Wireless LANs (WLANs)
- Extensions to wired LANs
- Carrier sense multiple access collision avoidance (CSMA/CA) as media access method
- Uses distributed coordinated function (DCF) for collision avoidance
- DCF is based on RF carrier sense, inter-frame spacing (IFS), and random wait timers
Wifi QoS standards
- 802.11e
  - IEEE standard
  - 0-7 priority levels
- Wifi Multimedia (WMM)
  - Four access categories
    - Platinum (voice) - 6 or 7 802.11e
    - Gold (video) - 4 or 5 802.11e
    - Silver (BE) - 0 or 3 802.11e
    - Bronze (Background) - 1 or 2 802.11e
- WMM and 802.11e replace DCF with EDCF
Cisco Split-MAC
- Splits functions between Lightweight access points (LWAPs) and WLAN controllers (WLCs)
- LWAPs handle real-time functions
  - Beacon generation
  - Probe transmission and response
  - Power management
  - 802.11e/WMM scheduling and queuing
  - Packet buffering
  - Encryption/decryption
  - Control frame/message processing
- WLCs handle non-real-time functions
  - Association/disassociation/reassociation
  - 802.11e/WMM resource reservation
  - 802.1x EAP
  - Key management
  - Authentication
  - Fragmentation
  - Ethernet-WLAN bridging
End-to-end QoS
- Step 1: WLC copies DSCP from switch to outer DSCP and outer 802.1p and sends to LWAP over LWAPP tunnel
- Step 2: LWAP copies outer DSCP from WLC to 802.11e/WMM field and sent to client
- Step 3: LWAP copies 802.11e/WMM value from the client to outer DSCP and sends it to WLC
- Step 4: WLC copies outer DSCP from WLAP to 802.1p (CoS) fields and sends it to the switch
Web interface (do you even need to know this?)
- Controller>QoS Profiles
  - Per-User Bandwidth Contracts - set avg data rate, burst data rate, avg real-time rate, and burst real-time rate
  - Over the Air QoS
    - Maximum RF usage per AP (%)
    - Queue Depth - queue size before dropping packets
    - Wired QoS Protocol - 802.1p or None
- Controller>WLANs>Edit
  - For each WLAN ID, set the QoS value: plat, gold, silver, bronze
  - WMM Policy
    - Disabled - 802.11e/WMM QoS requests are ignored
    - Allowed - 802.11e/WMM QoS requests are sent
    - Required - 802.11e/WMM QoS requests are required

Precedence on Aaron's Worthless Words

IIUC Notes - Inbound Dial Peer Matching

ONT Notes - QoS On Wireless Networks