Planet Technology G.SHDSL.bis Bridge Router GRT-504 - Manual (Page 52)

GRT-504 4-Wire G.SHDSL.bis Firewall Router User’s Manual
If the WAN Protocol is IPoA or EoA, leave the ISP parameters as default setting. The system will
ingore the information, but erasion or blank in default setting will cause system error.
VC-mux (VC-based Multiplexing): Each protocol is assigned to a specific virtual circuit. VC-based
multiplexing may be dominant in environments where dynamic creation of large numbers of ATM
VCs is fast and economical.
LLC (LLC-based Multiplexing): One VC carries multiptle protocols with protocol identifying
information being contained in each packet header. Deapite the extra bandwidth and processing
overhead, this method may be advantagrous if it is not practical to have a sepatate VC for each
carried protocol.
VPI (Virtual Path Identifier) is for set up ATM Permanent Virtual Channels(PVC).The valid range for
VPI is 0 to 255.
VCI (Virtual Channel Identifier is for set up ATM Permanent Virtual Channels(PVC). The valid
range for VCI is 32 to 65535 ( 0 to 31 is reserved for local management of ATM traffic.)
QoS (Quality of Service) class : The Traffic Management Specification V4.0 defines ATM service
cataloges that describe both the traffic transmitted by users onto a network as well as the Quailty of
Service that the network need to provide for that traffic. There have four class four choice: UBR,
CBR, rt-VBR and nrt-VBR. Select CBR to specify fixed bandwidth for voice or data traffic. Select
UBR for applications that are non-time sensitive, such as e-mail. Slect VBR for bursty traffic and
bandwidth sharing with other applications.
UBR (Unspecified Bit Rate) is the simplest service provided by ATM networks. There is no
guarantee of anything. It is a primary service used for transferring Internet traffic over the ATM
network.
CBR (Constant Bit Rate) is used by connections that requires a static amount of bandwidth that is
avilable during the connection life time. This bandwidth is characterized by Peak Cell Rate (PCR).
Based on the PCR of the CBR traffic, specific cell slots are assigned for the VC in the schedule
table. The ATM always sends a signle cell during the CBR connection’s assigned cell slot.
VBR-rt (Varible Bit Rate real-time) is intended for real-time applications, such as compressed
voice over IP and video comferencing, that require tightly constrained delays and delay variation.
VBR-rt is characterized by a peak cell rate (PCR), substained cell rate (SCR), and maximun burst
rate (MBR).
VBR-nrt (Varible Bit Rate non-real-time) is intended for non-real-time applications, such as FTP,
e-mail and browsing.
PCR (Peak Cell Rate) in kbps: The maximum rate at which you expect to transmit data, voice and
video. Consider PCR and MBS as a menas of reducing lantency, not increasing bandwidth. The
range of PCR is 384kbps to 11392kbps
SCR (Substained Cell Rate): The sustained rate at which you expect to transmit data, voice and
video. Consider SCR to be the true bandwidth of a VC and not the lone-term average traffic rate.
The range of SCR is 384kbps to 11392kbps.
MBS (Maximum Burst Size): Refers to the maximum number of cells that can be sent at the peak
rate. The range of MBS is 1 cell to 255 cells.
51