ZyXEL Communications PRESTIGE 153X Owner's manual

Prestige 153X
WAN Access Router
User's Guide Supplement
ZyXEL
TOTAL INTERNET ACCESS SOLUTION

Prestige 153X Supplement
User's Guide Supplement 1
N
Ne ew w F Fe ea at tu ur re es s: :
The Prestige 153X now supports Frame Relay! You may have up to 6 simultaneous frame relay connections
i.e., 3 PVCs on WAN port 1or 2. Each PVC has its own encapsulation type, DLCI (Data Link Connection
Identifier), CIR (Committed Information Rate) and EIR (Excess Information Rate). When frame relay is not
used, the WAN port can also be configured to run PPP over HDLC on a leased-sync line. The Connection
Type must be set to Leased-Sync to configure Frame Relay (so only P153X WAN ports 1 and/or 2 may be
used). Each of these ports can be configured as either the network side or the user side of the UNI interface.
The options for the Connection Type field are shown in the following table. UNI (User Network Interface)
defines the connection between user equipment and the Frame Relay network.
Network Frame relay is configured as the network side of the UNI interface.
User Frame relay is configured as the user side of the UNI interface.
Connection Type
None Runs PPP over HDLC without frame relay on a leased-sync line.
1.1 What is Frame Relay?
This is some background information on frame relay. Please skip ahead if you wish to begin configuring your
Prestige for Frame Relay right away.
Frame relay is a form of packet-switching technology that routes frames of information from source to
destination over a switching network owned by a carrier. Suppose a corporate network has 4 sites, site A, site
B, site C and site D (as shown in the next figure) and you need to interconnect these sites with both data links
and voice lines. As data traffic is relatively continuous throughout the day one solution (though inefficient)
would be to set up dedicated leased lines connecting each office as shown in Figure 1.
Figure 1 Dedicated Leased Lines – Multiple Sites

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The frame relay solution would be to rent short dedicated leased lines to the carriers frame relay access point
and then the carrier programs virtual circuits into the network between your sites.
Figure 2 Frame Relay Solution
Frames are “relayed” through switches in the network, creating basically a virtual private network (VPN)
between linked sites. This logical point-to-point circuit between customer sites is called a VC (virtual circuit)
of which there are two types. Permanent VCs (PVCs) have constant end points and need to be set up in
advance while switched VCs (SVCs) are set up on the fly as needed. The Prestige supports PVCs only.
1.1.1 Frame relay frame format
The frame format for frame relay is as follows.
Bytes
1 2-4 0-4,000 2 1
Flag Link Info Data FCS Flag
Upper DLCI (6 bits) C/R EA 0
Lower DLCI (4 bits) FECN BECN DE EA 1
Figure 3 Frame Relay Format
Each frame is described as follows:

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Table 1 Frame Relay Format
Frame Description
FLAG The flag field holds the “Start of frame” marker.
LINK INFO This field holds the logical connection address and control fields as described here:
DLCI DLCI (data link connection identifier) identifies the logical connections.
C/R Command/Response bit related to congestion control.
EA EA (extended address) is used to extend the header field to support DLCI addresses of
more than 10 bits.
FECN FECN (forward explicit congestion notification) warns receivers about network
congestion.
BECN BECN (backward explicit congestion notification) warns senders about network
congestion.
DE DE (discard eligibility) indicates whether frames can be discarded if the network is
congested.
DATA Control information or encapsulated data goes in this field.
FCS FCS (FRAME CHECK SEQUENCE) is a checksum used for error detection.
FLAG This flag field holds the “End of frame” marker.
1.1.2 Connection setup
The carrier gives you a specific DLCI (Data Link Connection Identifier) for each PVC which is a path
number of a portion of the PVC (the DLCI changes for each hop through the network), not the address of the
destination. It is a logical identifier with local significance only.
A management protocol called LMI (Local Management Interface) provides information about the status of
PVC-to-network access devices. It defines management frames for monitoring the integrity of a link and
whether a link is active or not.
The frame-relay network manages congestion by setting bits in frames that warn end devices that there is
congestion on the network. A bit called FECN (forward explicit congestion notification) is set to notify a
receiving system of congestion and a bit called BECN (backward explicit congestion notification) is set to
notify sending devices of congestion. In the latter case, the sending device will temporarily slow down or
stop transmissions.
1.1.3 Standards
The two main groups that create recommendations and standards in the telecommunications field are ITU – T
(International Telecommunication Union – Telecommunications Standardization Sector) and ANSI
(American National Standards Institute). Standards vary slightly for both organizations, so please select the

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correct standard in the Link Management field. Your Network Service Provider (NSP) should provide you
with this information.
1.2 How To Configure A P153X WAN Port For Frame Relay
Step 1. Go to menu 2 (shown next) and select either WAN Port 1 or 2. This brings you to Menu 2.1.
Frame relay can only be configured for leased synchronous connections.
Figure 4 Menu 2 – WAN Port Setup
Step 2. In Menu 2.1 go to the Connection Type field, press the [SPACEBAR] until it displays
Leased-Sync and then press [ENTER].
Figure 5 Menu 2.1 - Sync/Async WAN Port Setup
Menu 2.1 - Sync/Async WAN Port Setup
Modem Name= FR1
Active= Yes
Connection Type= Leased-Sync
Direction= N/A
Phone Number= N/A
Clock Source= External
Device Type= N/A
Port Speed= 115200
AT Command String:
Init= N/A
Edit Advanced Setup= Yes
Edit Frame Relay Options= Yes
Menu 2 - WAN Port Setup
1. Wan Port 1 (Sync/Async)
2. Wan Port 2 (Sync/Async)
3. Wan Port 3 (Async Only)
Select WAN Port:

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Step 3. Next, move the cursor to the Edit Frame Relay Options= field, press the [SPACEBAR] once
to display Yes and then press [ENTER]. This takes you to Menu 2.1.2 – Frame Relay Setup
shown next.
Figure 6 Menu 2.1.2 – Frame Relay Setup
Table 2 Menu 2.1.2 – Frame Relay Setup
Field Description Options
Link Type Choose User if the Prestige is on the user side of the
UNI (User Network Interface: defines the connection
between user equipment and the Frame Relay
network) and Network if it is on the network side of
the UNI. If your Prestige is connected to a service
provider choose User. If you are using two P153Xs
back-to-back, then one of them must be set to
Network and the other User. Choose None to
disable Frame Relay and run PPP over HDLC on the
leased-sync line.
User (default)
Network
None
Link Management Press the [SPACEBAR] and then [ENTER] to select
which standard is compatible with your Prestige. Both
the Prestige and the peer must use the same
standard. The standard defines functions that are
responsible for monitoring the up/down status and
error performance of an individual link. If failure
occurs, recovery actions are initiated for the
restoration of the failed link.
ITU-T(Q.933A)
ANSI(T1.617D)
Menu 2.1.2 – Frame Relay Setup
Line Type = User
Link Management = ANSI(T1.617D)
Press ENTER to Confirm or ESC to Cancel:
Press Space Bar to Toggle.

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1.3 How To Configure Frame Relay for Internet Access
1.3.1 Encapsulation
Be sure to use the encapsulation method required by your ISP. The Prestige supports the following methods.
RFC 1973 (PPP over FR)
RFC 1973 describes the use of Frame Relay for framing PPP encapsulated packets. Please refer to RFC 1973
for more information.
RFC 1490
RFC 1490 describes Multiprotocol over Frame Relay encapsulation which is an encapsulation method for
carrying network interconnect traffic (both bridging and routing) over a frame relay backbone. It also
describes a simple fragmentation procedure for carrying large frames over a frame relay network with a
smaller MTU (Maximum Transmission Unit).
1.3.2 DLCI
The carrier gives you a specific DLCI (data link connection identifier) for each PVC which is a path number
of a portion of the PVC (the DLCI changes for each hop through the network), not the address of the
destination. It is a logical identifier with local significance. Identifiers can range from 1 to 991 with
restrictions as shown in the following table. The default DLCI for the Prestige is 16 for the first PVC.
Table 3 Data Link Connection Identifiers
DLCI Usage
0 Channel Signaling
1-15 Reserved
16 – 991 Frame Relay
1.3.3 CIR (Committed Information Rate)
The carrier programs virtual circuits into the network between your sites and charges you for a specific level
of service called the committed information rate (CIR). The CIR is a negotiated rate and is basically a
guarantee that the carrier will always have that bandwidth available. The CIR limit for the Prestige is
256Kbps. The sum of CIRs from all channels in a line cannot exceed 256Kbps due to the processing limit of
the P153X CPU. In field tests, the P153X was found to have a maximum throughput (with Frame Relay) of
roughly 180Kbps.

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1.3.4 EIR (Excess Information Rate)
This is the burst capability of the connection, i.e., the maximum allowable data transfer rate. EIR must be
greater than or equal to the CIR.
Step 1. Go to Menu 4 – Internet Access Setup, move the cursor to the Connection Type field, press the
[SPACEBAR] until it displays Leased-Sync and then press [ENTER]. Frame relay can only be
configured for leased synchronous connections.
Figure 7 Menu 4 - Internet Access Setup
Step 2. Next, move the cursor to the Edit Frame Relay Options= field, press the [SPACEBAR] once to
display Yes and then press [ENTER]. This takes you to Menu 4.2 – Internet Setup Frame
Relay Options shown next.
Figure 8 Menu 4.2 – Internet Setup Frame Relay Options
Menu 4 - Internet Access Setup
ISP's Name= ISP
Connection Type= Leased-Sync
Leased Ports= 2
Pri Phone #= N/A
Sec Phone #= N/A
My Login= 1111
My Password= ********
Single User Account= No
IP Addr= N/A
Edit Frame Relay Options= Yes
Edit Script Options= N/A
Device Type= N/A
Nailed-Up Connection= N/A
Multilink= N/A
Idle Timeout= N/A
Press ENTER to Confirm or ESC to Cancel:
Menu 4.2 – Internet Setup Frame Relay Options
Encapsulation= RFC 1490
DLCI = 16
CIR (kbps)= 64
EIR (kbps)= 80
Enter here to CONFIRM or ESC to CANCEL:

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Table 4 Menu 4.2 – Internet Setup Frame Relay Options
Field Description Options/Examples
Encapsulation Be sure to use the encapsulation method required by
your ISP. The Prestige supports the following
methods. See section 1.3.1 for more information.
RFC 1973 (PPP over
FR)
RFC 1490
DLCI Enter the DLCI number required by your ISP. This is
a path number of a portion of the PVC (the DLCI
changes for each hop through the network), not the
address of the destination. The default DLCI for the
Prestige is 16 for the first PVC. See section 1.3.2 for
more information.
16
CIR (kbps) Enter the CIR as negotiated with your ISP. See
section 1.3.3 for more information.
64
EIR (kbps) Enter the EIR as negotiated with your ISP. See
section 1.3.4 for more information.
80
1.4 How To Configure Frame Relay For A Remote Node
Configuring Frame Relay for a remote node is similar to configuring Frame Relay for Internet Access.
Step 1. Go to Menu 11.1 – Remote Node Profile, move the cursor to the Connection Type field, press
the [SPACEBAR] until it displays Leased-Sync and then press [ENTER]. Frame relay can
only be configured for leased synchronous connections.

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Figure 9 Menu 11.1 – Remote Node Profile
Step 2. Next, move the cursor to the Edit Frame Relay Options= field, press the [SPACEBAR] once to
display Yes and then press [ENTER]. This takes you to Menu 11.4 – Remote Node Frame
Relay Options shown next.
Figure 10 Menu 11.4 - Remote Node Frame Relay Options
The fields in this table are the same as described in Table 4 above.
1.5 Status Display For Frame Relay
Menu 24.1 - System Maintenance – Status has been modified to incorporate Frame Relay information. Port
and DLCI numbers are shown for each PVC. CIR is displayed in the Speed field. When frame relay is
deployed, the WAN IP address for each PVC (with the DLCI appended) is displayed in turn in the
corresponding WAN Port IP Addr field. The LAN Packet Which Triggered Last Call field has been
Menu 11.1 – Remote Node Profile
Rem Node Name= rn1 Route= IP
Active= Yes Bridge= No
Connection Type= Leased-Sync
Leased Ports= 1 Edit PPP Options= No
Backup Line Call Direction= Both Rem IP Addr= 192.168.1.1
Device Type= N/A Edit IP/IPX/Bridge= No
Incoming:
Rem Login= 1111 Telco Option:
Rem Password= ******** Edit Frame Relay Options= Yes
Outgoing:
My Login= 2222 Session Options:
My Password= ******** Edit Filter Sets= No
Authen= N/A Idle Timeout(sec)= 300
Primary Phone #= N/A
Secondary Phone #= N/A
Press ENTER to Confirm or ESC to Cancel:
Menu 11.4 - Remote Node Frame Relay Options
Encapsulation= RFC 1490
DLCI = 16
CIR (kbps)= 64
EIR (kbps)= 80
Enter here to CONFIRM or ESC to CANCEL: