VOIP Slides Flashcards
what are 4 main layer protocalls
TCP
UDP
RTP
what are main layer 3 protocols
IP
IPX
DDP-datagram delivery protocol used in AppleTalk
what are main layer 2 protocols
ethernet
frame realy
ATM
what are the layer 1 protocols
DS1 DS3
SONET
TDM protocols
where will you find a class 5 switch
PTSN LOCAL netowrk
What is a class 4 switch
PSTN Tandem Switch
What is the function of a class 3 switch
Switching Long Distance Calls
Where will you find IMT trunks
Between LD (class 3) switches
Why were Feature Group D trunks created?
To allow equal access and billing without having to dial a LD access code
The three devices required to set up a VoIP call are:
media gateway
media gatwaye controller
signaling proxy
A call between a VoIP end point and a traditional PSTN phone requires a handoff between
IP and PTSN
Can the media gateway controller reside in any location as long as it has Internet connectivity?
YESSS
Does voice over IP switch features reside within the local media gateway?
NOOOO
Two common signaling protocols utilized in the VoIP network are ________ and ________.
MegaCo
SIP
Switch features reside within the local media gateway.
false
A SIP Proxy is used to:
nterpret and step up calls, tear down calls — all signaling functions related to calls.
The media gateway controller performs the same functions as a class ________ switch.
5
gatewat controller used for
Call setup and teardown •Managing traffic flows between networks •Controlling multiple MGs in the network
The MGC interfaces with MGs, Application Servers and the Signaling Gateway
application servers do some of the following
•Billing •Automatic Call Distributor •Voice Mail •Unified Messaging •Other service
Media Telephone Adapter/Analog Telephone Adapters perform the following functions
•Conversion of the VoIP packet into an analog voice signal •Generates Dial Tone •A to D and D to A conversion
The MTA/ATA talks to the MGC through the MG
Media Telephone Adapter/Analog Telephone Adapters
VOIP signaling methods
Peer to Peer: Session Initiation Protocol, H.323 Gives the end point enough smarts to handle the call processing
Master/Slave: Megaco/H.248 and MGCP Requires a central controller for call processing
SIP is what layer
layer 7 application
how does Megaco work
Megaco/H.248 are master-slave protocols used to talk to the SS-7 network through the Signaling Gateway to talk to the PSTN.
what kind of packet flows in VOIP
Real Time Protocol is used to carry real-time traffic across the network
Used for voice and video
RTP organizes packets to ensure the packets arrive in the correct order and at the correct time to be used without error.
Real Time Control Protocol is used in conjunction with RTP to carry network information related to RTP flow for troubleshooting
quality of service and tagging
Using priority tags in the Layer 3 IP traffic prioritizes voice traffic in the IP network
Diff-Serv, CoS, QoS and DSCP are all different terms for this tagging.
Without the tag traffic is views as best-effort in the network
explain the equipment of VOIP
MEdia Gateway
Media Gateway controller
Singaling proxy
Application server
