Contributed February 20, 2002 by Bishwajit Mazumder" <email@example.com>
Questionnaire on IP Telephony Installed by Bank It is understood that traditional telephone in fixed bandwidth was carried out across a circuit switched PBX infrastructure while other dynamic data applications are consolidated over an IP based backbone. IP telephony converges these two separate infrastructures. The technology used in the IP WAN allows for tremendous flexibility in the design of the intranet. IP protocol is the underlying carrier of data, voice and video, a number of technologies such as Point to point Protocol (PPP), frame Relay, Asynchronous Transfer Mode (ATM), dark Fibre, Digital Subscriber line (DSL), Synchronous Optical Network (SONET), Wave Division Multiplexing (WDM) may be used to construct the network. Questionnaire Explanations Auditee Comments
Is the architecture adopted for this purpose has solution for convergence of data, voice and video Please specify the fundamental Logically it should be like components of the architecture Clients Applications Infrastructure Is the path of the call is transparent to Say like if IP WAN is full the end user or unavailable, the call would automatically be routed across the PSTN What are the technologies being used to Techniques such as: ensure QoS for voice traffic. Low Latency Queuing Weighted Fair Queuing Priority queuing, etc. Are any tools being used to ensure that voice traffic remains of high quality Will the user be allowed to access the voice mail and e-mail from the same server Is there any migration policy to migrate the existing voice and data networks to the converged network. If yes, then please give the details Is there any uniform dialling plans for Irrespective of which side legacy and new system as well of the network you are on, the incoming and outgoing calls from the outside worlds appears to be exactly the same In a LAN environment, how is the interconnection of a desktop in a
converged network being done. Are we using a Catalyst switchpowered patch panel for interconnection. If yes, then please give details. Is there a UPS in the wiring closet for backing up the voice and data network. How is the IP addressing being handled, given to the need adding new IP phone devices keeping the existing IP addresses intact. Is any classification is being used to differentiate at all points in the network between voice and data traffic. If yes, then give details. Whether there is any ability to change the Layer 2 and Layer 3 classification parameters in terms of class of service and type of service Is the network been designed as truly fault tolerant, fast, converging networks. WAN Links Are proper queuing techniques being applied so that delay and drop sensitive traffic pass through, relative to drop tolerant data applications Are standard based fragmentation techniques being used for data packet fragmentation Is there any possibility of central site could overrun both the physical bandwidth and committed information rate (CIR) bandwidth of remote site Is there any admission control being exercised to ensure QoS
Are we using 802.1q virtual LAN and catalyst switches.
At Layer 2 802.1p defines Class of Service At Layer 3, the IP layer defines type of service
To prevent this a feature called traffic shaping is used on the central site router. Admission Control effectively prevents too much voice from being sent down a WAN that does not have enough bandwidth to handle it
Are we using voice traffic compression What are we doing for IP overhead. Are we using any tool to compress IP headers