Chpter 7 Routing with Frme Rely, X.25, nd SNA This chpter discusses Frme Rely, X.25, nd SNA Routing. Also see the following: Section 4.2, Identifying the BANDIT in the Network Section 4.3, Defining Globl Pths Section 10.2.2, Ping Step 4 (Trce Route) in Section 10.1, System Tools 7.1 Routing The Routing option llows you to perform ddress mpping, or routing, by estblishing routing tbles tht guide pckets on their pths through the network. The unit cn route pckets conforming to the IP, IPX, Frme Rely, X.25, Annex G (tht is, X.25 over Frme Rely), nd SNA protocols. This chpter provides detiled informtion nd procedures for configuring Frme Rely, X.25, nd SNA routing.
7-2 Chpter 7: Routing with Frme Rely, X.25, nd SNA Note: IP nd IPX routing re discussed in Chpter 6, IP Routing nd IPX Routing. The units re designed to look t the ddress portion of these pckets nd route them to the corresponding port, ccording to the routing tbles. If routing entries hve lredy been mde, you re given the option to dd, modify, or delete entries. 1 On the Min Menu, select Advnced Configurtions, then Routing. When you select Routing on the Advnced Configurtions menu, the Configure Routing menu is displyed: Configure Routing ------------------ 1) IP Routing 2) IPX Routing 3) Frme Rely Routing 4) X.25 Routing 5) SNA Routing Enter Choice : 7.2 Frme Rely You cn configure use of synchronous or synchronous Frme Rely in the BANDIT devices. Trnsporting dt over Frme Rely network hs mny benefits: Cn crry mny connections over single line. Shres bndwidth with multiple pplictions nd/or cll sessions. Cn hndle bursty trffic. Provides high-speed nd low-dely similr to Time Division Multiplexing (TDM). Provides ccess to public Frme Rely services (not bsed on usge) tht re usully lower cost thn those for lesed lines.
Frme Rely 7-3 The BANDIT provides cost-efficient mens for connecting legcy equipment to Frme Rely network by trnslting protocols into formt tht cn be trnsmitted over Frme Rely network. After the unit trnsltes the dt, it routes the dt cross the Frme Rely network to nother unit or Frme Rely-comptible device. When it reches the destintion device, the dt is trnslted bck to the originl protocol. The BANDIT cn lso concentrte nd switch multiple sources of Frme Rely trffic simultneously. Note: Before configuring Frme Rely prmeters, study the informtion in Section 7.2.2, Hertbet Polling, nd Section 7.2.3, FstPROTECT with Priority. 7.2.1 Using DLCIs for Frme Rely Becuse single physicl connection to Frme Rely network cn support lrge number of pplictions or sessions, method is required to uniquely identify the dt flow ssocited with ech ppliction or session. This is performed in Frme Rely by wy of logicl connections or Virtul Circuits (VCs). Frme Rely s VCs re clled Dt Link Connections (DLCs). Ech DLC hs n identifying number, known s Dt Link Connection Identifier (DLCI). This DLCI is used in the Frme Rely pcket heder s n ddress for the dt contined in the pcket. Although Frme Rely supports switched service tht llows connections to be temporrily estblished, most Frme Rely services (nd equipment used to provision the services) implement DLCs s Permnent Virtul Circuits (PVCs) i.e., the connections re preconfigured by the network opertor t the time of subscription. The ssigned DLCIs must be configured for your unit. It is importnt to note tht DLCI hs locl significnce only; the other end of PVC probbly hs different DLCI. For exmple, suppose PVC hs been provisioned between site A nd site B. The PVC is ssigned DLCI of 100 t site A, nd DLCI of 500 t site B. Dt sent from site A with DLCI of 100 is crried over the first PVC to rrive t site B. Similrly, dt sent from site B must use DLCI of 500 to rrive t site A. The Frme Rely interfce stndrd defines mximum of 1024 possible DLCIs. Of these, two DLCIs (0 nd 1023) hve been reserved for signling, nd 30 DLCIs (1 to 15 nd 1008 to 1022) hve been reserved for future use. Tht leves 992 DLCIs (16 to 1007) vilble for subscriber use on ech physicl interfce to the network.
7-4 Chpter 7: Routing with Frme Rely, X.25, nd SNA 7.2.2 Hertbet Polling Hertbet polling is the procedure by which the user device requests PVC sttus informtion nd detects fults in the network connection or the userto-network interfce, s follows: Note: This informtion cn be cquired from the Frme Rely crrier. The defults set in the unit re pproprite for most networks. 1 Every T 1 seconds (time vlue 1, in seconds), the user device sends STATUS_ENQUIRY messge to the network. This messge is typiclly request for the Sequence Number Exchnge Only (report type = 00000001 ). 2 Every N 1 polling intervls, the user device sends Full Sttus Messge request (report type = 00000000 ) to the network. 3 The network responds to the STATUS_ENQUIRY messge with STATUS messge. The STATUS report type mtches the report type of the STATUS_ENQUIRY messge i.e., either Sequence Number Exchnge Only or Full Sttus Messge. 4 The unit exmines the STATUS messge, nd updtes its internl dtbse ccording to the PVC Sttus Informtion Element (IE). 5 An error hs occurred if: The report type of the STATUS messge does not mtch the report type of the most recently trnsmitted STATUS_ENQUIRY request. The unit does not receive STATUS messge within T 1 seconds fter sending the STATUS_ENQUIRY messge. The network device does not receive STATUS_ENQUIRY messge within T 2 seconds of the lst STATUS_ENQUIRY. 7.2.3 FstPROTECT with Priority FstPROTECT is congestion mngement feture tht llows trffic to be discrded to protect the unit from memory overlod. In the congestion mngement scheme, only dt going out Frme Rely port is subject to discrding. The discrd lgorithm discrds pckets, bsed on the number of memory buffers vilble nd ccording to the priority ssigned to tht
Frme Rely 7-5 pcket. At 25% of vilble buffers, both Low nd Medium priority dt re discrded. At 10% of vilble buffers, High priority trffic is discrded. At 20 or fewer buffers, Immedite priority dt is lso discrded. 7.2.4 Frme Rely Routing This procedure configures Frme Rely ports nd their corresponding DLCIs when the BANDIT is used s Frme Rely switch. Note: To configure the Frme Rely protocol (in ddition to Frme Rely routing), see Section 7.2.5, Frme Rely Protocol. 1 To configure Frme Rely routing, do the following: b c Log in to the BANDIT. (See Section 3.2, Connecting Supervisory Terminl nd Logging in to the BANDIT.) On the Min Menu, select Advnced Configurtions. (See Section 3.3, The Min Menu.) On the Advnced Configurtions Menu, select Routing. (See Section 3.3.4, The Advnced Configurtions Menu.) d On the Routing menu, select Frme Rely Routing. (See Section 7.1, Routing.) If the routing tble is empty, prompts will sk you to dd pth nme nd to indicte the priority for outgoing trffic. Empty Frme Rely Routing Tble Add Frme Rely Routing Tble Entry Add First Frme Rely Pth Nme Enter Pth Nme (1 to 10 Chrcters): FR01
7-6 Chpter 7: Routing with Frme Rely, X.25, nd SNA 2 Type nme for Frme Rely pth. If the pth nme does not exist, prompt sks whether you wish to dd it to the Pth tble. Pth Nme Does Not Exist In GPT Tble. To Add Globl Pth Entry, Press 'Y'or Enter. Press Escpe Otherwise. y 3 Answer y (or n, if you choose not to dd the pth nme to the tble). A prompt lets you choose the pth type. Globl Pth Types ------------------ 1) X25 SVC 2) X25 PVC 3) Frme Rely PVC 4) Port Type 5) IP/UDP Enter Choice : (1 to 5)[1] : 3 4 Choose Frme Rely PVC. A prompt sks which port the pth uses. Enter FR Port Number (L (LAN),W (WAN),M (MODEM), S (SERIAL),): S 5 Choose the port tht uses Frme Rely (in this exmple, we choose the seril port). A prompt sks for the Frme Rely DLCI. Enter FR DLCI Number (16-1007) : 16
Frme Rely 7-7 6 Enter the DLCI ssigned by the Frme Rely crrier. A prompt sks whether there is bckup DLCI. Do You Wnt Bckup DLCI? (Y/N)[N] : N 7 Answer y or n to indicte whether there is bckup DLCI. If there is bckup DLCI, you must enter its informtion. When configurtion of the pth is complete, messge indictes tht the pth hs been dded to the Globl Pth Tble (GPT). GPT Entry dded. Then prompt sks for the priority of trffic on the DLCI. Enter Priority ( defult = Medium ) for outgoing trffic on DLCI 16, port: SERIAL Enter Choice : 3 (1) Immedite (2) High (3) Medium (4) Low 8 Select the DLCI s trffic priority. A messge indictes the DLCI informtion. Priority set to Medium for DLCI 16 on port: SERIAL
7-8 Chpter 7: Routing with Frme Rely, X.25, nd SNA Then the BANDIT sks for nother pth nme. Add Second Frme Rely Pth Nme Enter Pth Nme (1 to 10 Chrcters): 9 Do one of the following: If you wish to enter nother pth nme, return to Step 2 b If there is not nother pth nme, press Escpe. A prompt indictes tht configurtion of the Frme Rely Routing Tble hs completed. Frme Rely Routing Tble Hndling Complete When the routing tble hs been set up, the Configure Routing menu is displyed gin. Configure Routing ------------------ 1) IP Routing 2) IPX Routing 3) Frme Rely Routing 4) X.25 Routing Enter Choice : 10 When you hve finished configuring Frme Rely routing, press Escpe to return to the Routing menu. (See Section 7.1, Routing.)
Frme Rely 7-9 7.2.5 Frme Rely Protocol Note: If you re using the Frme Rely port for Frme Rely Pssthrough or for Frme-Rely-to-Frme-Rely Switching, you must complete the Frme Rely Routing Tble (see Section 7.2.4, Frme Rely Routing). See Section 9.2.7, Frme Rely Sttistics, for description of the sttistics used to monitor this protocol. 1 From the Min Menu, select Advnced Configurtions, Dt Configurtions >> Seril Port >> Undefine Logicl Port. Then select Protocol >> Frme Rely. When you select Frme Rely from the Logicl Port Protocol Selection Menu, the following menu is displyed: Frme Rely Mngement Prmeters : SERIAL ----------------------------------------------- 1) Type : Synchronous Frme Rely 2) Speed : 56000 3) Protocol : Adptive Mngement - User 4) Vlue N1 : 6 5) Vlue N2 : 3 6) Vlue N3 : 4 7) Timer T1 : 10 8) Timer T2 : 15 9) Priority / CIR Enforcement : Disbled A) High to Medium Rtio : 4:1 B) Medium to Low Rtio : 4:1 C) DLCI CIR Informtion D) FRF-12 Frgmenttion : Disbled Enter Choice : 2 Select Type. This prmeter specifies whether the clock type is synchronous or synchronous. The following menu options re displyed:
7-10 Chpter 7: Routing with Frme Rely, X.25, nd SNA Frme Rely Type 1) Synchronous 2) Asynchronous Enter Choice : Select the type of clocking you wnt. 3 Select Speed. This prmeter sets the clock speed. One of the following list of speeds is displyed: Synchronous speeds: Configure Synchronous Clock Speed 1) 2400 2) 4800 3) 9600 4) 19200 5) 38400 6) 48000 7) 56000 8) 64000 9) 96000 A) 128000 B) 192000 C) 256000 D) 384000 E) 512000 F) 768000 G) 1024000 H) 1536000 I) 2048000 Enter Choice:
Frme Rely 7-11 Asynchronous speeds: Configure Asynchronous Clock Speed ----------------------------------- 1) 1200 2) 2400 3) 4800 4) 9600 5) 19200 6) 38400 7) 48000 8) 57600 9) 115200 A) 230400 Enter Choice : Note: When the port is configured s DTE, s opposed to DCE, the prmeters menu reflects tht the speed is provided by the device connected to the unit. In this cse, you do not need to configure speed. If you ttempt to configure the speed, the following messge is displyed, nd you re returned to the prmeters menu: Port is DTE, Cn Not Chnge Speed 4 Protocol. This option llows you to select the Frme Rely mngement protocol you re using. Select Protocol. The following menu is displyed: Frme Rely Mngement Protocol -------------------------------- 1) ANSI T1.617 Annex D - User 2) CCITT Q.933 Annex A - User 3) LMI - User 4) Adptive Mngement - User 5) ANSI T1.617 Annex D - Network 6) CCITT Q.933 Annex A - Network 7) LMI - Network 8) Adptive Mngement - Network 9) None Enter Choice :
7-12 Chpter 7: Routing with Frme Rely, X.25, nd SNA Note: Frme Rely cn lso be run without mngement protocol. Your Frme Rely crrier or Network Administrtor cn tell you which protocol to use. The defult is Adptive Mngement - User. Select the Frme Rely Mngement protocol you wnt to use. The new protocol is displyed on the Frme Rely Mngement Prmeters menu. Note: The Frme Rely Mngement protocol provides ccess procedures for the detection nd notifiction of: Addition of PVC Deletion of PVC Avilbility (ctive stte) of configured PVC Unvilbility (inctive stte) of configured PVC Locl In-chnnel Signling link relibility errors Locl In-chnnel Signling link protocol errors
Frme Rely 7-13 Note: Currently there re three mngement stndrds nd two dditionl options. The mngement stndrds include: ITU Q.933 Annex A ANSI T1.617 Annex D Frme Rely Forum s Locl Mngement Interfce (LMI) Annex A nd Annex D re quite similr; however, they re incomptible with LMI. Annex A nd Annex D use DLCI 0, wheres LMI uses DLCI 1023. Our products cn support either the Network or User side of these protocols. There re two dditionl Frme Rely network mngement options: Adptive Mngement/User nd Adptive Mngement/ Network. These protocols llow the unit to utomticlly detect whether ANSI T1.617 Annex-D or LMI is being used. Once LMI or Annex D hs been identified, the port continues to use tht protocol until the unit is reset. If in Network mode, the unit determines its ctul protocol from the first received Sttus Enquiry. If in User mode, the unit lterntes between issuing Annex-D nd LMI Sttus Enquiries until Sttus Response is received. The Frme Rely sttistics screen indictes which protocol is being used. 5 Select Vlue N1. This prmeter determines the number of Sttus Inquiry/Sttus Polling Cycles tht occur before Full Sttus Polling Cycle is initited. Enter Desired Frme Rely Vlue N1 (1-255): Note: The Vlue nd Timer defults were set to mtch the Frme Rely Forum stndrds. They should not be chnged unless necessry. N1 (LMI) or N391 (T1.617 Annex D or A) re the N prmeters tht require Full Sttus Messge in STATUS_ENQUIRY Hertbet Polling process. LMI, Annex A nd Annex D Defults = 6 intervls.
7-14 Chpter 7: Routing with Frme Rely, X.25, nd SNA Enter the Frme Rely vlue you wnt to use nd press Enter. This chnges the vlue to the number you typed nd returns you to the Frme Rely Mngement Prmeters menu. 6 Select Vlue N2. This prmeter sets the error threshold count (N2). The error threshold count (N2) reflects the number of Locl Inchnnel Signling Link Relibility Errors tht re llowed to occur during Sliding Monitored Events Window before the link is considered down. Enter Desired Frme Rely Vlue N2 (1-10): Note: A Monitored Event, from the network s perspective, is n event such s the expirtion of timer, the receipt of Sttus Enquiry messge, etc. The Vlue nd Timer defults were set to mtch the Frme Rely Forum stndrds. They should not be chnged unless necessry. Enter the Frme Rely vlue you wnt to use nd press Enter. This chnges the vlue to the number you typed nd returns you to the Frme Rely Mngement Prmeters menu. Note: LMI Defult = 2 errors Annex D N392 Defult = 3 errors Annex A N392 Defult = 3 errors 7 Select Vlue N3. This prmeter specifies the size of the Sliding Monitored Events Count ( Monitored Event, from the network s perspective, is n event.
Frme Rely 7-15 Enter Desired Frme Rely Vlue N3 (1-10): Note: The Vlue nd Timer defults were set to mtch the Frme Rely Forum stndrds. They should not be chnged unless necessry. Note: Vlue N3 is the number of monitored events (such s the expirtion of timer, the receipt of Sttus Enquiry messge, etc.) within which predetermined number of N2 errors must be detected before the link is considered down. This vlue lso reflects the number of monitored events tht must occur with no N2 errors before the link is considered bck up. Enter the Frme Rely vlue you wnt to use nd press Enter. This chnges the vlue to the number you typed nd returns you to the Frme Rely Mngement Prmeters menu. Note: LMI Defult = 4 events Annex D N393 Defult = 4 events Annex A N393 Defult = 4 events 8 Timer T1. This prmeter sets the Link Integrity Verifiction Timer, which indictes how frequently the unit should initite Sttus Inquiry Messge. Select Timer T1. Enter Desired Frme Rely Timer T1 (5-30):
7-16 Chpter 7: Routing with Frme Rely, X.25, nd SNA Note: The Vlue nd Timer defults were set to mtch the Frme Rely Forum stndrds. They should not be chnged unless necessry. Note: When N2 errors of the lst T1 number of monitored events contin n error, the device declres filed link. For exmple, ssuming the defult vlues of N2 = 2 nd T1 = 10 seconds, it tkes 20 seconds to detect filed link. All PVCs on the filed link re set to inctive. T1 is the length of the time spent witing for STATUS messge fter sending STATUS_ENQUIRY (user devices). Note: The device continues to send STATUS_ENQUIRY messges. The link is removed from the filed stte fter receiving N3 consecutive messges without n error. For exmple, ssuming the defult vlues of N3 = 4 nd T1 = 10, it would tke 40 seconds for the link to restore to ctive sttus. When the link is restored to ctive sttus, the network device immeditely sets ll PVCs on the link to ctive. The user device sets the PVCs to the sttus indicted by the first PVC sttus Informtion Element tht is successfully received. Type the Frme Rely vlue you wnt to use nd press Enter. This chnges the vlue to the number you typed nd returns you to the Frme Rely Mngement Prmeters menu. Note: LMI Defult = 10 seconds Annex D T391 Defult = 10 seconds Annex A T391 Defult = 10 seconds
Frme Rely 7-17 9 Timer T2. This option llows you to set the Polling Verifiction Timer, which indictes the length of time the network should wit between Sttus Inquiry messges. Select Timer T2. Enter Desired Frme Rely Timer T2 (5-30): Note: The Vlue nd Timer defults were set to mtch the Frme Rely Forum stndrds. They should not be chnged unless necessry. Note: If no Sttus Inquiry messge is received within T2 seconds, the network records n error. Type the Frme Rely vlue you wnt to use nd press Enter. This chnges the vlue to the number you typed nd returns you to the Frme Rely Mngement Prmeters menu. Note: LMI Defult = 15 seconds Annex D T392 Defult = 15 seconds Annex A T392 Defult = 15 seconds 10 Select Priority/CIR Enforcement. This prmeter enbles or disbles priority queuing on the Frme Rely port. Priority queuing llows you to ssign Immedite, High, Medium, or Low priority to dt being trnsmitted. Priorities cn be set for given DLCI s protocol or ddress rnge, or for n entire DLCI, without restrictions. For exmple, you cn ssign priority to prticulr protocol. In this wy, you might ssign SNA trffic high priority level, IPX trffic medium priority, nd IP trffic low priority.
7-18 Chpter 7: Routing with Frme Rely, X.25, nd SNA You cn ssign different priority levels to distinct ddress rnges going out the sme DLCI. You might do this in the IP Routing Tble when configuring IP trffic. For instnce, you might ssign high priority to IP trffic with given ddress rnge going to users nd ssign low priority to IP trffic with different ddress rnge going to printer. This feture cnnot be used with routing protocols tht utomticlly build their own routing tbles, such s IP RIP, or IPX, unless you configure the priority on their interfces individully. In some cses, you cn ssign priority to given DLCI, so tht ny trffic trveling through tht DLCI mintins the ssigned priority, regrdless of dt type or ddress. For exmple, you might set up Frme Rely routing tble, ssigning high priority to Network DLCI being used to send trffic to n ATM mchine nd low priority to different Network DLCI used to send trffic to server. In this tble, you cnnot ssign two or more priorities to the sme DLCI s you cn in the IP Routing Tble exmple bove. When buffer spce is low, s in the cse of network mlfunction, dt my be discrded in the following order: low, medium, high nd then immedite priority. This phenomenon occurs regrdless of whether the queuing function is enbled or disbled in the Priority field. You cn monitor dt throughput nd the reception of BECN bits, which indicte congestion in the Frme Rely network, on n overll or DLCI bsis. Sttistics for vilble nd excess bndwidth re mintined nd reclculted s needed for ech DLCI. The following options re displyed: Frme Rely Priority / CIR Enforcement -------------------------------------- 1) Enble 2) Disble Enter Choice : Select the option you wnt. 11 Select High to Medium Rtio or Medium to Low Rtio.
Frme Rely 7-19 High to Medium Rtio nd Medium to Low Rtio. These options define byte rtio of high-to-medium or medium-to-low trffic. The Priority level is set ccording to verge rtio of bytes. However, ll trnsmissions re sent in whole frmes. Suppose trnsmission contins 230 bytes, nd these 230 bytes re composed of: 2 frmes t 160 nd 10 bytes, respectively, of High priority 40 bytes of Medium priority trffic 20 bytes of Low priority trffic. If the high-to-medium rtio is set to 4:1, nd the medium-to-low rtio is set to 2:1, the trnsmission would rotte between priority levels in n order similr to the following: 160 bytes of High priority trffic is trnsmitted first 40 bytes of Medium priority trffic is trnsmitted next 20 bytes of Low priority trffic is trnsmitted next 10 bytes of High priority trffic is trnsmitted next. With every trnsmission, the unit checks for trffic of ll priority levels in order to pply the rtio you hve specified. However, if ll of the trffic in queue is set t the sme priority level, this trffic is sent continully until trffic with nother priority level requests trnsmission. At this point, the unit pplies the rtio to the existing trffic in queue. One of the following trffic rtio menus is displyed: High To Medium Priority Rtio Selection 1) 1:1 2) 2:1 3) 4:1 4) 8:1 5) 16:1 6) 32:1 7) 64:1 Enter Choice :
7-20 Chpter 7: Routing with Frme Rely, X.25, nd SNA Medium To Low Priority Rtio Selection 1) 1:1 2) 2:1 3) 4:1 4) 8:1 5) 16:1 6) 32:1 7) 64:1 Enter Choice : Select the rtio you wnt to use. Note: The cycle of rtios is High to Medium to Low, nd then to High gin. This llows lower priority trffic from the first trnsmission to be sent before dditionl higher priority level trffic from the second trnsmission is sent. 12 DLCI CIR Informtion. When configuring DLCIs, you cn llocte designted mount of committed bndwidth to DLCI, s long s this bndwidth does not exceed the speed of the Frme Rely line. This committed bndwidth, clled Committed Informtion Rte (CIR), is the mount of bndwidth DLCI is gurnteed to hve vilble t ll times for trnsmitting dt. If the DLCI ttempts to send more dt thn cn be crried within the boundry of its CIR, such s in the cse of bursty trffic, there is no gurntee tht this excess dt is sent. You must configure n excess bndwidth rnge for the DLCI. If trffic is within the excess bndwidth rnge, it is delivered s long s the Frme Rely line hs spce vilble to crry it. Both CIR nd excess bndwidth is negotited with the service provider nd must be greed upon nd purchsed before you configure the unit with these vlues. Any trffic exceeding the excess bndwidth rnge (B e ) cn be utomticlly discrded by the service provider, regrdless of vilble bndwidth. The priority queuing function monitors ech DLCI s committed nd excess CIR. Trffic being trnsmitted within its CIR is trnsmitted before trffic using ny llotted excess bndwidth.
Frme Rely 7-21 Trnsmissions re mde in the following order of priority: CIR Immedite CIR High CIR Medium CIR Low Excess Immedite Excess High Excess Medium Excess Low Note: Immedite priority dt, s long s it is within its llocted CIR, preempts ll other trffic in the queue (except mngement trffic). The DLCI CIR Informtion option llows you to configure CIR nd excess bndwidth for ech DLCI. Select the DLCI CIR Informtion field on the Frme Rely Mngement Prmeters Menu. The following prompts re displyed: Tble Is Empty. Add Tble Entry Add DCLI Informtion Enter DLCI Number (16-1007): Enter the first DLCI number nd press ENTER. Enter CIR (committed informtion rte) in bits per second: b CIR. Type the CIR you negotited with the service provider, nd press Enter.
7-22 Chpter 7: Routing with Frme Rely, X.25, nd SNA Enter Bc (committed burst size) in bits: c Committed Burst Size (Bc). Type the Burst Size tht you negotited with the service provider. Bc is the number of bits you cn trnsmit within given time (T) in seconds. (T usully equls one second.) Bc/ T = CIR Note: If T = 1 second, you cn trnsmit X number of bits (Bc), wit one second nd trnsmit nother X number of bits (Bc). In this mnner, the number of bps trnsmitted never exceeds the mount of bndwidth the DLCI hs been llocted. Bndwidth Bc CIR Time Note: If T = 2 seconds, however, you cn trnsmit twice s mny bits per second, but you must wit twice s long before you cn trnsmit more bits. d Enter the Committed Burst Size (Bc) nd press ENTER. Enter Be (excess burst size) in bits: e Burst Excess Rte, B(e). Type the Burst Excess rte you negotited with the service provider. B(e) is the number of bits you cn trnsmit within given time (T) in seconds. B(e)/T = CIR. The vlue for B(e) is typiclly the line speed less the CIR nd Bc.
Frme Rely 7-23 Note: If the line speed is 56000 bps nd the CIR nd is 4000 bps, the B(e) is 52000 bits, ssuming T = 1. f Enter the B(e) vlue. When ll vlues for DLCI re entered, the following prompt is displyed nd you hve the opportunity to enter vlues for dditionl DLCIs: Entry Added Enter DLCI Number (16-1007): g When you re finished entering vlues for ll DLCIs, press Escpe to view the tble of DLCI entries. You re given the opportunity to dd, chnge, or delete ny entry. h After you review the tble nd mke ny necessry chnges, press Escpe gin to return to the Frme Rely Mngement Prmeters Menu. 13 FRF-12 Frgmenttion. Frgmenttion of dt pckets on Frme Rely llows for proper voice nd dt qulity while shring the sme port. If you wish, enble nd configure this feture. FRF.12 Prmeters : SERIAL ----------------------------- 1) Frgmenttion : Disbled 2) Frgmenttion Type : Buffer Boundry 3) Frgmenttion Size : 128 bytes Enter Choice : Note: To sve the new configurtion, you must WRITE nd RESET. (See Section 3.3.7, Write Configurtion, nd Section 3.3.8, Reset Unit.)
7-24 Chpter 7: Routing with Frme Rely, X.25, nd SNA 7.2.6 Frme Rely Unicsting nd Multicsting A stndrd Frme Rely trnsmission uses the sme DLCI to trnsmit to nd receive from one specified device. This is the defult in the BANDIT. The BANDIT cn lso set up unicst trnsmission. The unicst feture trnsmits on one DLCI (to one specified device) nd receives on nother DLCI (from tht sme device). The unicst feture is specificlly gered for trnsmissions over stellite networks, to sve bndwidth nd support most of the Frme Rely pplictions. (However, unicst cn lso be used over ground-bsed networks.) You cn lso set up multicst trnsmissions (to two or more specified recipients). This option provides the cpbility for device to trnsmit the sme ppliction dt to multiple DLCIs or the bility for single device to receive dt from multiple DLCIs. This cn be used s replcement for multidrop modems. At present, this feture is pplicble only to dt; it cnnot be used to multicst voice. (The multicst feture is not gered for nor limited to stellite networks.) Frme Rely multicsting cn be used to send informtion from centrl point to severl endpoints or to ll endpoints. Note: The BANDIT s Frme Rely does not brodcst trnsmissions (tht is, it does not trnsmit to unspecified recipients, of ny number). How to Configure Frme Rely Unicsting or Multicsting In this procedure, first we set up three stndrd Frme Rely pths. With ech stndrd pth, you use one DLCI to send nd receive informtion from single remote device. Then we configure unicst trnsmission, which includes n outgoing Frme Rely pth (to the remote device) nd n incoming Frme Rely pth (from the remote device), on different DLCIs. Finlly, we configure multicst group to include ll three stndrd pths nd the outgoing unicst pth. The locl device sends multicst trnsmission to ll remote devices t the sme time. 1 From the Min Menu, select Advnced Configurtions, Globl Pths.
Frme Rely 7-25 If the Globl Pth Tble lredy contins records, the tble is displyed. Go to Step 8. If the Globl Pth Tble is empty, the following prompt is displyed. Empty Globl Pth Tble Add Globl Pth Tble Entry Enter Pth Nme (1 to 10 Chrcters): 2 Do ll of the following: Type the nme of Frme Rely pth (for exmple, remote1) nd press Enter. The Globl Pth Types menu is displyed. Globl Pth Types ------------------ 1) X25 SVC 2) X25 PVC 3) Frme Rely PVC 4) Port Type 5) IP/UDP 6) Voice 7) FR Multicst Pth Enter Choice : (1 to 7)[1] : b Select Frme Rely PVC. The following prompt is displyed. Enter Port Number (S(SERIAL),E(EXPANSION),R = RDU Ports,1-24): c Select the port for the Frme Rely PVC.
7-26 Chpter 7: Routing with Frme Rely, X.25, nd SNA The following prompt is displyed. Enter FR DLCI Number (16-1007) : d Indicte the DLCI for this pth. The following prompt is displyed. Any Advnced Fetures? (B - Bckup Pth H - Help) (U - FrmeRely Unicsting N - None) [N] : e For stndrd pth, select None. The following messge is displyed. Entry dded. To View the entry press ESC or To Add nother entry Enter Pth Nme (1 to 10 Chrcters): 3 Set up nother stndrd Frme Rely pth, clled remote2. (See Step 2.) 4 Then set up nother stndrd Frme Rely pth, clled remote3. (See Step 2.) 5 Then set up unicst Frme Rely pth, s follows: Type the nme of Frme Rely pth (for exmple, uni-out), nd press Enter. The Globl Pth Types menu is displyed.
Frme Rely 7-27 Globl Pth Types ------------------ 1) X25 SVC 2) X25 PVC 3) Frme Rely PVC 4) Port Type 5) IP/UDP 6) Voice 7) FR Multicst Pth Enter Choice : (1 to 7)[1] : b Select Frme Rely PVC. The following prompt is displyed. Enter Port Number (S(SERIAL),E(EXPANSION),R = RDU Ports,1-24): c Select the port for the Frme Rely PVC. The following prompt is displyed. Enter FR DLCI Number (16-1007) : d Indicte the DLCI for this pth. The following prompt is displyed. Any Advnced Fetures? (B - Bckup Pth H - Help) (U - FrmeRely Unicsting N - None) [N] : e For unicst pth, select Frme Rely Unicsting.
7-28 Chpter 7: Routing with Frme Rely, X.25, nd SNA The following messge is displyed. Is this pth Outgoing or Incoming? f Select Outgoing. The following messge is displyed. Enter Incoming Pth Nme (1 to 10 Chrcters): g Type the nme of the Frme Rely pth for the other direction (for exmple, uni-in), nd press Enter. The Globl Pth Types menu is displyed. Globl Pth Types ------------------ 1) X25 SVC 2) X25 PVC 3) Frme Rely PVC 4) Port Type 5) IP/UDP 6) Voice 7) FR Multicst Pth Enter Choice : (1 to 7)[1] : h Select Frme Rely PVC. The following prompt is displyed. Enter Port Number (S(SERIAL),E(EXPANSION),R = RDU Ports,1-24): i Select the port for the incoming Frme Rely PVC.
Frme Rely 7-29 The following prompt is displyed. Enter FR DLCI Number (16-1007) : j Indicte the DLCI for the incoming pth. This DLCI cnnot be the sme s the outgoing DLCI. The following prompt is displyed. Entry dded. To View the entry press ESC or To Add nother entry Enter Pth Nme (1 to 10 Chrcters): 6 Add multicst Frme Rely pth, s follows: Type the pth nme (for exmple, multi). The Globl Pth Types menu is displyed. Globl Pth Types ------------------ 1) X25 SVC 2) X25 PVC 3) Frme Rely PVC 4) Port Type 5) IP/UDP 6) Voice 7) FR Multicst Pth Enter Choice : (1 to 7)[1] : b Select FR Multicst Pth. The following prompt is displyed.
7-30 Chpter 7: Routing with Frme Rely, X.25, nd SNA Enter the Member Pths... Enter Pth Nme (1 to 10 Chrcters): c Type the first pth (remote1) for this multicst group, nd press Enter. The following prompt is displyed. Wnt to dd more pths? (Y/N)[Y] : d Do one of the following: To dd nother pth to the multicst group, nswer Y. Repet Step 6c. (Do this to dd the pths remote2, remote3, nd uni-out). When you hve finished dding pths, nswer N. Entry dded. To View the entry press ESC or To Add nother entry Enter Pth Nme (1 to 10 Chrcters): 7 Press Escpe. The Globl Pth Tble is displyed.
X.25 Routing 7-31 Entry Pth Nme PthType Port DLCI ----- ---------- -------- ---- ----- 1 remote1 FR PVC S 16 2 remote2 FR PVC S 17 3 remote3 FR PVC S 18 4 uni-out FR PVC S 19 Entry Pth Nme PthType ----- ---------- -------- 5 multi FR MULTICAST PATH Add, Modify, or Delete n Entry? (Enter A, M, or D): 8 Do one of the following: To return to the Advnced Configurtions menu, press Escpe. b To dd n entry, type. Go to Step 2. c d To modify n entry, type m nd follow the instructions on the screen. To delete n entry, type d nd follow the instructions on the screen. 7.3 X.25 Routing Note: To configure the X.25 protocol (in ddition to X.25 routing), see Section 7.4, X.25 Protocol. 1 To configure X.25 routing, do the following: b c d Log in to the BANDIT. (See Section 3.2, Connecting Supervisory Terminl nd Logging in to the BANDIT.) On the Min Menu, select Advnced Configurtions. (See Section 3.3, The Min Menu.) On the Advnced Configurtions Menu, select Routing. (See Section 3.3.4, The Advnced Configurtions Menu.) On the Routing menu, select X.25 Routing. (See Section 7.1, Routing.)
7-32 Chpter 7: Routing with Frme Rely, X.25, nd SNA The X.25 Routing Configurtion menu ppers. This menu lets you configure the X.25 globl prmeters, including the X.25 switching tble. You cn configure the prmeters s described in the following steps. X.25 Routing Configurtion --------------------------- 1) X.25 Switching Tble 2) Proprietory Trffic Idle VC Timer : 180 3) SNA Trffic Idle VC Timer (seconds) : 180 4) IP/IPX Trffic Idle VC Timer (seconds) : 180 5) IP/IPX SVC Retry Timer (seconds) : 60 6) IP/IPX SVC Retry Count : 3 7) X.121 Sub-Address Length : 2 Enter Choice : 2 Select X.25 Switching Tble to enter n X.121 destintion ddress to be mpped to given port. Outbound clls destined to this ddress will be routed through this port. Observe the following ddressing rules: Addresses must use digits; tht is, permitted chrcters re 0 (zero) to 9. Addresses cnnot strt with 0 (zero). A question mrk (?) is one-digit wildcrd. It cn be used to replce only one digit. You cn hve ny number of question mrks. For exmple, if n ddress ssigned to port is 44?4, vlid ddresses include 4404, 4474, 4424, etc., but not 44004. An sterisk (*) is multidigit wildcrd, to replce ny number of digits, from none to the entire ddress. In ddition, you cn use n sterisk in s mny positions s you wish. For exmple, if n ddress ssigned to port is 12*, the port ccepts ny ddress whose first two digits re 12. It does not mtter how mny digits, if ny, follow the 12. Vlid ddresses include 12, 128, 1209, nd 12309, but not 1029. Or if n ddress on port is configured s 55*9, vlid ddresses include 559, 5509, nd 551239, but not 55001122933. It does not mtter how mny digits, if ny, fll between the initil 55 nd the 9, but no digits re llowed to follow the 9. (However, 55*9* does llow digits following the 9.)
X.25 Routing 7-33 Empty X25NEW Switching Tble Add X25NEW Switching Tble Entry Enter Remote X121 Address(1 to 15 digits): Enter the X.121 destintion ddress of the remote device or network, nd press Enter. Enter X25Sw Port Number (S(SERIAL),E(EXPANSION),R = RDU Ports,1-24): b Enter the port tht X.25 clls will use to rech this remote X.121 ddress. The following messge nd prompt re displyed. Entry dded. To View the entry press ESC or To Add nother entry Enter Remote X121 Address(1 to 15 digits): 3 Do one of the following: To dd nother record to the tble, go to Step. b To view the X.25 Switching Tble, press Escpe. You cn continue entering ddresses or mke chnges to n existing entry. When you finish, press Escpe to return to the X.25 Routing Configurtion menu.
7-34 Chpter 7: Routing with Frme Rely, X.25, nd SNA Num Destintion Out Port X121 Address 1 1234 SERIAL Add, Modify, or Delete n Entry? (Enter A, M, or D): 4 Select Proprietry Trffic Idle VC Timer to specify the number of seconds the line my remin idle before the cll is clered, when no chrcters re being trnsmitted in either direction. The following option is displyed: Enter Prop. Prot. Idle Tmr(0 to 600)[180] : Note: Proprietry Trffic Idle VC Timer is specific only to the following proprietry protocols: Async Encpsultion, Bit Sync Encpsultion, nd Byte Sync Encpsultion. Type the number of seconds the line my remin idle, nd press Enter. 5 Select SNA Trffic Idle VC Timer to set the mximum number of seconds the X.25 connection estblished for SNA QLLC my remin idle. The following option is displyed: Enter SNA Idle VC Timer(0 to 600)[180] : Type the number of seconds for this timer, nd press Enter.
X.25 Routing 7-35 Note: When the timer expires, the cll is clered. If you type 0 (zero) in this field, the timer is disbled nd the virtul circuit lwys remins up. The X.25 Routing Configurtion menu is redisplyed. 6 Select IP/IPX Trffic Idle VC Timer to set the mximum number of seconds n IP or IPX connection my remin idle. Enter Idle VC Timer(0 to 600)[180] : Type the number of seconds for this timer, nd press Enter. Note: When the timer expires, the cll is clered. The X.25 Routing Configurtion menu is redisplyed. 7 Select IP/IPX SVC Retry Timer to set the mximum number of seconds to wit before the next IP or IPX cll ttempt cn be mde if the previous cll ttempt ws unsuccessful. Enter IP/IPX SVC Retry Timer(0 to 600)[60] : Type the number of seconds nd press Enter. The X.25 Routing Configurtion menu is redisplyed.
7-36 Chpter 7: Routing with Frme Rely, X.25, nd SNA Note: When the timer expires, the cll will be ttempted gin. (To limit the number of retries, see Step 8.) 8 Select IP/IPX SVC Retry Count to set the number of times n IP or IPX cll ttempt will be mde if the previous cll ttempt ws unsuccessful. Enter IP/IPX SVC Retry Count (0 to 10)[3] : Type the number of retries nd press Enter. The X.25 Routing Configurtion menu is redisplyed. Note: If the cll is not successful fter the configured number of cll ttempts, the next IP or IPX cll will be triggered by the IP/IPX trffic. 9 Select X.121 Sub-Address Length to specify the mximum number of digits tht sub-ddress cn hve. Enter X.121 Sub-Address Length(1 to 5)[2] : Enter the number of digits llowed in the sub-ddress, nd press Enter. The X.25 Routing Configurtion menu is redisplyed. 10 When you hve finished configuring X.25 routing, press Escpe to return to the Routing menu. (See Section 7.1, Routing.)
X.25 Protocol 7-37 11 Press Escpe until you return to the Min Menu. 7.4 X.25 Protocol The BANDIT supports use of synchronous or synchronous X.25. The X.25 protocol cn be used for switching or for crrying QLLC, IP, or IPX trffic. Note: In ddition to stndrd X.25, the BANDIT cn perform some dditionl pplictions of X.25. See the following sections: Section 5.14, X.25 over IP Section 5.15.3, Converting AX.25 to MATIP. 7.4.1 X.25 Level-1 Configurtion Note: You must complete the X.25 Routing Tble with the ddresses of ll units in your network. (See Section 7.3, X.25 Routing.) See Section 9.2.17, X.25 Sttistics, for description of the sttistics monitored in this protocol. 1 From the Min Menu, select Advnced Configurtions, Dt Configurtions; then select port. Then select Undefine Logicl Port >> Protocol >> X.25+. When you select X.25+ from the Logicl Port Protocol Selection Menu, the following menu is displyed: X.25 Prmeters : Port 1 ---------------------------- 1) X.25 Level-1 Configurtion 2) X.25 Level-2 (LAPB) Configurtion 3) X.25 Level-3 (PLP) Configurtion Enter Choice :
7-38 Chpter 7: Routing with Frme Rely, X.25, nd SNA 2 Enter the number of the X.25 level you wnt to configure. The corresponding menu is displyed on the screen. Note: Mke sure t lest one X.25 port is enbled when Frme Rely is not vilble. 1 Select X.25 Level-1 Configurtion. This option llows you to configure the physicl level of X.25. A menu similr to the following menu is displyed: X.25 Level-1 Prmeters : SERIAL ------------------------------------- 1) Type : Synchronous 2) Speed : 9600 3) Frme Rely Globl Pth Nme : N/A 4) Encpsultion : N/A Enter Choice : Note: A virtul port s menu does not show speed. b Select Type; then select Synchronous or Asynchronous. Speed. This option llows you to set the synchronous clock speed tht units configured s DCE will use to provide clocking to the user s equipment. Select Speed. Note: The Speed field is pplicble only if you re configuring physicl port. If you re configuring logicl port, proceed to Step 2. One of the following menus is displyed:
X.25 Protocol 7-39 Synchronous: Configure Synchronous Clock Speed ---------------------------------- 1) 2400 2) 4800 3) 9600 4) 19200 5) 38400 6) 48000 7) 56000 8) 64000 9) 96000 A) 128000 B) 192000 C) 256000 D) 384000 E) 512000 F) 768000 G) 1024000 H) 1536000 I) 2048000 Enter Choice : Asynchronous: Configure Asynchronous Clock Speed ----------------------------------- 1) 1200 2) 2400 3) 4800 4) 9600 5) 19200 6) 38400 7) 48000 8) 57600 9) 115200 A) 230400 Enter Choice : Note: When the port is configured s DTE, s opposed to DCE, the prmeters menu reflects tht the speed is provided by the device connected to the unit. In this cse, you do not need to configure speed. If you ttempt to configure the speed, the following messge is displyed nd you re returned to the prmeters menu:
7-40 Chpter 7: Routing with Frme Rely, X.25, nd SNA Port is DTE, Cn Not Chnge Speed 2 Select Globl Pth Nme nd indicte the pth this port will use. See Section 4.3, Defining Globl Pths. Note: This field is not pplicble for physicl port. 3 Select Encpsultion nd indicte the encpsultion method to use. X.25 Level-1 Prmeters : Port 4 --------------------------------------- 1) Type : Synchronous 2) Frme Rely Globl Pth Nme : <NONE> 3) Encpsultion : Annex G Enter Choice : Note: This field is not pplicble for physicl port. Use n encpsultion method only on virtul port. 4 Press Escpe to return to the X.25 Prmeters menu. 7.4.2 X.25 Level-2 Configurtion 1 Select X.25 Level-2 Prmeters (LAPB) Configurtion. This option llows you to configure the link level of the X.25 protocol. The following menu is displyed:
X.25 Protocol 7-41 X.25 Level-2 Prmeters : SERIAL ----------------------------------- 1) Interfce Mode(DTE/DCE) : DTE 2) Link Activtor(DTE/DCE) : DTE 3) Acknowledgement Timer (T1)(seconds) : 3 4) Response Timer (T2)(tenths of second) : 2 5) Disconnect Timer (T3)(seconds) : 20 6) Retry Count (N2) : 10 7) Frme Sequencing : Modulo 8 8) Trnsmit Window Size : 7 9) Receive Window Size : 7 Enter Choice : 2 Select Interfce Mode (DTE/DCE). This option llows you to specify whether the Interfce Mode of the link level is DCE or DTE. Note: In X.25, the Interfce Mode must be opposite the mode of the network or device to which the unit is connected. When the unit is connecting to public network, the unit must be in DTE mode. If locl unit is connected to n X.25 device, which is configured for DCE, then the locl unit should be configured for DTE. If the X.25 device is configured for DTE, then the locl unit should be configured for DCE. Enter IF Mode vlue 1->DTE or 2->DCE : (1 to 2)[1] : 3 Select the correct mode nd press ENTER. 4 Select Link Activtor (DTE/DCE). This option llows you to specify which node (the node configured s DCE or the node configured s DTE) will initite or ctivte the link. If the Interfce Mode mtches the Link Activtor mode, this unit will send SABMs. If the two modes do not mtch, this unit will wit for SABMs.
7-42 Chpter 7: Routing with Frme Rely, X.25, nd SNA Enter Link Activtor 1->DTE or 2->DCE : (1 to 2)[1] : Note: This defult vlue is set to universlly ccepted vlue. If you chnge the defult vlue, mke sure the new setting is consistent with the device or network to which the unit is connected. Select the mode (DCE or DTE) of the node tht will initite the link, press ENTER. The X.25 Prmeters menu is redisplyed. 5 Select Acknowledgement Timer (T1) (seconds). This option llows you to set the mximum number of seconds tht the Level 2 protocol must wit for cknowledgment of receipt of trnsmitted frme. Enter T1 Timer vlue(1 to 10)[3] : Enter the number of seconds to wit for cknowledgment nd press ENTER. If no cknowledgment is received, the unit will re-send the frme configured number of times. If n cknowledgment is not received fter N2 retries, the link is disconnected. To set N2 (the number of retries), see Step 8.) 6 Select Response Timer (T2) (tenths of second). This option llows you to set the mximum number of time units (in tenths of second) to wit before sending n cknowledgment for sequenced I-frme tht hs been received. The following option is displyed:
X.25 Protocol 7-43 Enter T2 Timer(0 to 100)[2] : Enter the number of tenths of second nd press Enter. Note: A vlue of zero mens there will be no dely in cknowledgment genertion. 7 Select Disconnect Timer (T3). This option llows you to set the number of seconds to wit before the link is considered disconnected. The following option is displyed: Enter T3 Disconnect Timer(30 to 180)[60] : Enter the number of seconds nd press Enter. 8 Select Retry Count (N2). This option llows you to set the number of times frme is retrnsmitted when no cknowledgment is received nd when the T1 timer hs expired. (To set the T1 timer, see Step 5.) If n cknowledgment is not received fter N2 retries, the link is disconnected. The following option is displyed: Enter N2 Retrnsmit Count(1 to 30)[10] : Enter the number of retries llowed nd press Enter. The X.25 Prmeters menu is redisplyed.
7-44 Chpter 7: Routing with Frme Rely, X.25, nd SNA 9 Select Frme Sequencing. This option llows you to set the frme sequencing number. All frmes must be ssigned number tht designtes the individul frme s proper sequentil plcement within strem of dt to ensure tht they rrive t their destintion in their originl order nd re not shuffled. The X.25 protocol llows two mesures of consecutive frme numbers: Modulo 8 nd Modulo 128. Modulo 8 llows frme numbers to strt t 0 nd end t 7. After frme number 7 is received t its destintion, the number ssignment of frmes begins gin t 0. Modulo 128 llows frme numbers to strt t 0 nd end t 127. After frme number 127 is received t its destintion, the number ssignments of frmes begins gin t 0. Enter the Sequence Number Modulo 8 --> 1, Modulo 128 --> 2(1 to 2)[1] : Enter the sequence number nd press Enter. The X.25 Level-2 Prmeters menu is redisplyed. 10 Select Trnsmit Window Size. This option llows you to set the mximum number of sequenced I-frmes this unit is llowed to hve outstnding (outstnding frmes re frmes tht hve been sent but not cknowledged). For Exmple: Suppose you ssign vlue of three (3) in the Trnsmit Window Size field. This unit cn trnsmit up to three frmes without receiving cknowledgment for ny of them. Once it hs three uncknowledged frmes outstnding, the window is considered blocked nd it cnnot trnsmit ny more frme until t lest one frme is cknowledged. As ech frme is cknowledged, nother frme cn be sent, s long s the totl number of frmes tht hve been sent but not cknowledged (the totl number of frmes outstnding) does not exceed three. It is importnt, then, tht the Trnsmit Window Size of given unit port mtch the Receive Window Size of the connected device. Note: The Trnsmit Window Size must be less thn the number in the Frme Sequencing field.
X.25 Protocol 7-45 Enter Trnsmit Window Size(1 to 127)[7] : Enter the trnsmit window size nd press ENTER. 11 Select Receive Window Size. This option llows you to set the mximum number of sequenced I-frmes this unit is llowed to receive before it must send n cknowledgment. Enter Receiver Window Size(1 to 127)[7] : Suppose the device to which this unit is connected hs been configured with Trnsmit Window Size of 7. The connected device in this exmple, then, cn hve mximum of seven frmes outstnding. (Outstnding frmes re frmes tht hve been sent but hve not been cknowledged.) The unit for which you re configuring the Receive Window Size cn withhold cknowledgment, then, for up to seven frmes. If it receives seven frmes nd does not cknowledge ny of them, the window is considered blocked nd it cnnot receive more frmes until it cknowledges t lest one of those frmes. As this unit cknowledges ech frme, it cn receive nother frme, s long s the totl number of frmes tht hve been received but not cknowledged (the totl number of frmes outstnding) does not exceed seven. It is importnt, then, tht the Receive Window Size of given unit port mtch the Trnsmit Window Size of the connected device. Note: The Receive Window Size must be less thn the number in the Frme Sequencing field.
7-46 Chpter 7: Routing with Frme Rely, X.25, nd SNA Enter the receive window size nd press Enter. The X.25 Level-2 Prmeters menu is redisplyed. 12 Press Escpe to return to the X.25 Prmeters menu. 7.4.3 X.25 Level-3 Configurtion 1 Select X.25 Level-3 (PLP) Configurtion to configure the pcket level of the X.25 protocol. The following menu is displyed: X.25 Level-3 Prmeters : SERIAL ----------------------------------- 1) Interfce Mode(DTE/DCE) : DTE 2) Trnsmit Pcket Size : 128 3) Receive Pcket Size : 128 4) Pcket Sequencing : Modulo 8 5) Trnsmit Window Size : 2 6) Receive Window Size : 2 7) Pcket Restrt Timer (T20)(seconds) : 60 8) Pcket Cll Request Timer (T21)(seconds ) : 60 9) Pcket Reset Request Timer (T22)(seconds) : 60 A) Pcket Cler Request Timer (T23)(seconds) : 60 B) Incoming Cll Fcility Options : PASS THROUGH FACILITIES C) Outgoing Cll Fcility Options : PASS THROUGH FACILITIES D) High SVC Chnnel Number : 10 E) Low SVC Chnnel Number : 1 F) High PVC Chnnel Number : 0 G) Mximum Number of Active SVCs Permitted : 10 Enter Choice : Note: Defult vlues re set to universlly ccepted vlues. If you chnge defult vlue, mke sure the new setting is consistent with the device or network to which the unit is connected. 2 Select Interfce Mode. This option llows you to set the pcket level Interfce Mode s DCE or DTE.
X.25 Protocol 7-47 Note: In X.25, the Interfce Mode must be opposite the mode of the network or device to which the unit is connected. For exmple, if locl unit is connected to n X.25 device, which is configured for DCE, then the locl unit should be configured for DTE. If the X.25 device is configured for DTE, then the locl unit should be configured for DCE. The DTE/DCE selection governs the selection of LCNs s clls re plced. DTE strts t the highest LCN nd uses LCNs in descending order. DCE strts t the lowest LCN nd uses LCNs in scending order. LCN 0 is reserved for RESTART pckets tht use LCN 0. LCNs re llocted in this mnner to prevent cll collision. Enter IF Mode vlue 1->DTE or 2->DCE : (1 to 2)[1] : Select the mode you wnt nd press Enter. The X.25 Level-3 Prmeters menu is redisplyed. 3 Select Trnsmit Pcket Size. This option llows you to set the mximum length (in octets) of pckets tht cn be sent on the line. The following option is displyed: Enter Trnsmitting Pcket Size(128 to 4096)[128] : Enter the size of the trnsmitting pcket nd press Enter. The X.25 Level-3 Prmeters menu is redisplyed. 4 Select Receive Pcket Size. This option llows you to set the mximum length (in octets) of pckets tht cn be received on the line.