Download Cisco.PracticeDumps.200-310.2018-05-22.1e.345q.vcex

   
  
Interference detection and avoidance: As Cisco LWAPs monitor all channels, interference is detected by a predefined threshold (10 percent by default). Interference can be generated by rogue APs, microwaves, cordless telephones, Bluetooth devices, neighboring WLANs, or other electronic devices.

A Cisco ASR is used to terminate Teleworker solutions, not a 2900 series router. 
Hybrid teleworker uses Aironet, Advanced teleworker uses 880, both use IP phones. 
google: "at_a_glance_c45-652500.pdf" for details
The Cisco Virtual Office Solution for the Enterprise Teleworker is implemented using the Cisco 800 series ISRs. Each ISR has integrated switch ports that then connect to the user’s broadband connection. The solution uses a permanent always-on IPsec VPN tunnel back to the corporate network. This architecture provides for centralized IT security management, corporate-pushed security policies, and integrated identity services. In addition, this solution supports the enterprise teleworker needs through advanced applications such as voice and video. For example, the enterprise teleworker can take advantage of toll bypass, voicemail, and advanced IP phone features not available in the PSTN. 
Enterprise Teleworker Module 
The enterprise teleworker module consists of a small office or a mobile user who needs to access services of the enterprise campus. As shown in Figure 2-14, mobile users connect from their homes, hotels, or other locations using dialup or Internet access lines. VPN clients are used to allow mobile users to securely access enterprise applications. The Cisco Virtual Office solution provides a solution for teleworkers that is centrally managed using small integrated service routers (ISR) in the VPN solution. IP phone capabilities are also provided in the Cisco Virtual Office solution, providing corporate voice services for mobile users. 
   

Small Branch Design 
The small branch design is recommended for branch offices that do not require hardware redundancy and that have a small user base supporting up to 50 users. This profile consists of an access router providing WAN services and connections for the LAN services. 
The Layer 3 WAN services are based on the WAN and Internet deployment model. A T1 is used for the primary link, and an ADSL secondary link is used for backup. Other network fundamentals are supported, such as EIGRP, floating static routes, and QoS for bandwidth protection. 
Medium Branch Design 
The medium branch design is recommended for branch offices of 50 to 100 users, which is similar to the small branch but with an additional access router in the WAN edge (slightly larger) allowing for redundancy services. 
Large Branch Design 
The large branch design is the largest of the branch profiles, supporting between 100 and 1000 users. This design profile is similar to the medium branch design in that it also provides dual access routers in the WAN edge. In addition, dual Adaptive Security Appliances (ASA) are used for stateful firewall filtering, and dual distribution switches provide the multilayer switching component. The WAN services use an MPLS deployment model with dual WAN links into the WAN cloud. 
Cisco Press CCDA 640-864 Official Certification Guide Fourth Edition, Chapter 7

For the Enterprise Campus, DHCP and internal DNS servers should be located in the Server Farm and they should be redundant. External DNS servers can be placed redundantly at the service provider facility and at the Enterprise branch. 
   

Without filters there is possibility of routing loops. 
Link: http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009487e.shtml

While the human ear can sense sounds from 20 to 20, 000 Hz, and speech encompasses sounds from about 200 to 9000 Hz, the telephone channel was designed to operate at about 300 to 3400 Hz. This economical range carries enough fidelity to allow callers to identify the party at the far end and sense their mood. Nyquist decided to extend the digitization to 4000 Hz, to capture higher-frequency sounds that the telephone channel may deliver. Therefore, the highest frequency for voice is 4000 Hz. According to Nyquist theory, we must double the highest frequency, so 2x4kHz = 8kHz. 
Each sample will be encoded into a 8-bit code. Therefore 8kHz x 8-bit code = 64 Kbps (notice about the unit Kbps: 8kHz = 8000 samples per second so 8000 x 8-bit = 64000 bit per second = 64 Kilobit per second = 64 Kbps)
Link: http://encyclopedia2.thefreedictionary.com/Nyquist+theorem
Note:
Nyquist theory:
“When sampling a signal (e.g., converting from an analog signal to digital), the sampling frequency must be greater than twice the bandwidth of the input signal in order to be able to reconstruct the original perfectly from the sampled version.”

Validating user authentication should be implemented as close to the source as possible, with an emphasis on strong authentication for access from untrusted networks. Access rules should enforce policy deployed throughout the network with the following guidelines: 
Source-specific rules with any type destinations should be applied as close to the source as possible. 
Destination-specific rules with any type sources should be applied as close to the destination as possible. 
Mixed rules integrating both source and destination should be used as close to the source as possible. 
An integral part of identity and access control deployments is to allow only the necessary access. Highly distributed rules allow for greater granularity and scalability but, unfortunately, increase the management complexity. On the other hand, centralized rule deployment eases management but lacks flexibility and scalability. 
Practicing “defense in depth” by using security mechanisms that back each other up is an important concept to understand. For example, the perimeter Internet routers should use ACLs to filter packets in addition to the firewall inspecting packets at a deeper level. 
Cisco Press CCDA 640-864 Official Certification Guide Fourth Edition, Chapter 13

With such an arrangement there is no complex mesh of access points & controllers. 
Link: http://www.cisco.com/web/learning/le31/le46/cln/qlm/CCDA/design/understanding-wireless-network-controller-technology-3/player.html
N+N WLC Redundancy 
With N+N redundancy, shown in Figure 5-14, an equal number of controllers hack up each other. For example, a pair of WLCs on one floor serves as a backup to a second pair on another floor. The top WLC is primary for API and AP2 and secondary for AP3 and AP4. The bottom WLC is primary for AP3 and AP4 and secondary for API and AP2. There should be enough capacity on each controller to manage a failover situation. 
    
  
N+N+1 WLC Redundancy 
With N+N+1 redundancy, shown in Figure 5-15, an equal number of controllers back up each other (as with N+N), plus a backup WLC is configured as the tertiary WLC for the APs. N+N+1 redundancy functions the same as N+N redundancy plus a tertiary controller that backs up the secondary controllers. The tertiary WLC is placed in the data center or network operations center