Voice Carrier. Preparing Your Network For Voice Carrier VoIP. Version 1.0. Page 1 of 15

Transcription

1 Vice Carrier Page 1 f 15

2 Last Edited: 3/11/2014 Summary This dcument is intended t help Vice Carrier Partners and Custmers prepare their netwrks fr implementatin f Vice Carrier Services. The cncepts discussed in this dcument can be applied t installatin f any Vice Carrier prduct and are intended t educate the reader n the varius, general netwrk cmpnents and als prvide infrmatin n Vice Carrier specific requirements and cncepts. Upn reading this dcument the custmer r Partner shuld have a better understanding f hw t evaluate and prepare a netwrk prir t attempting t deply Vice Carrier services. In additin, the terms and cncepts intrduced in this dcument are intended t help Vice Carrier partners determine where they may need t spend additinal time researching and educating themselves n the cncepts that are instrumental in becming a successful user and evangelist fr Vice Carrier SIP based VIP services. Descriptin f Netwrk Cmpnents and Terms By adhering t the recmmendatins prvided in this dcument, Vice Carrier Partners and Custmers will be able t prepare their netwrk fr deplying Vice Carrier Services. While implementatin mdels may vary slightly based n prduct, general recmmendatins will be prvided that will help ensure successful implementatin and peratin f Vice Carrier services. Internet Service Prvider (ISP) - All Vice Carrier services are IP based and as a result rely heavily, if nt entirely, n the custmer s cnnectin t the internet. This cnnectin is prvided by the custmer s ISP and can range frm dedicated fiber r metr Ethernet t cable internet r DSL. The chice f ISP is ne f the mst imprtant chices that can be made when making the decisin t mve t VIP since the speed and stability f the ISP will likely have the greatest impact n the quality f service. IP Addresses - IP addresses are used t uniquely identify devices n a netwrk and are classified as either public r private IP addresses as defined in RFC 1918 ( The custmer s ISP will typically distribute ne r mre public IP address t the custmer and the public IP will be assigned t the WAN interface f the custmer s ruter r mdem/ruter. Mdem - a mdem is prvided with services such as cable internet and DSL and is the demark between the ISP and the custmer s internal netwrk. An Ethernet handff is typically prvided frm the mdem t the custmer. In sme cases the mdem prvided by the ISP actually cntains ruter and/r firewall functinality as described belw. When a separate ruter/firewall is t be used by the custmer, the mdem must be set t bridge mde t avid issues with duble NAT (Netwrk Address Translatin) that can negatively impact vice traffic. Page 2 f 15

3 Ruter - In the purest sense a ruter is a device that rutes packets between varius IP subnets/netwrks. A ruter makes the decisin t rute traffic based n its ruting table which is ppulated either via static rutes which are prvided manually during cnfiguratin r via ruting prtcls which autmatically exchange rute infrmatin between ruters based n netwrk cnfiguratin and status. Mst ruters that will be deplyed by Vice Carrier custmers will likely use static rute and will simply rute between the ISP n the WAN side f the ruter and the custmer s internal netwrk n the LAN side f the ruter. Switch - Switches are generally layer 2 devices that are deplyed in Lcal Area Netwrk (LAN) envirnments and used t aggregate device cnnectins n the LAN. Switches can be used t segment Ethernet netwrks and cnnect a large number f devices n a Layer 2 netwrk t a layer 3 netwrk which is typically represented by the use f a ruter. While sme higher end switches can act as a ruter, mst switches yu will wrk with d nt make IP ruting decisins r perfrm firewall functins such as filtering and NAT. Vice Carrier VIP Basics While there are many different signaling and media prtcls that can be used fr VIP traffic, all cnversatins regarding Vice Carrier VIP will assume that SIP/UDP is being used as the signaling methd and RTP/UDP is being used fr all media. When wrking with VIP service there are tw types f IP traffic that need t be handled prperly in rder fr call setup and vice cmmunicatin t be successful. SIP: SIP stands fr Sessin Initiatin Prtcl. SIP is used fr call setup, tear dwn, and all ther signaling required fr the management and manipulatin f VIP service. While SIP primarily uses UDP prt 5060 fr transprt, Vice Carrier recmmends cnfiguring yur ruter/firewall s that prts are priritized utbund t the internet and with the recmmended settings described in this dcument s that the apprpriate tw way SIP cmmunicatin can be maintained.. NOTE: It is nt typically required t explicitly permit any traffic inbund as this is usually implicitly permitted due t the utbund cmmunicatin f the device n the custmer site as described in the Hw VIP cmmunicatin wrks sectin belw. RTP: RTP stands fr Real-Time-Prtcl and is the actual vice traffic that is transmitted nce the call is set up between the tw endpints. Many calls can be ging n at the same time frm ne site t anther s a wide range f prts are typically available fr RTP traffic s that each call can be designated a unique prt. While a smaller subset f prts is typically needed, UDP prts 10,000-20,000 are earmarked fr RTP traffic and can be used when establishing rules t allw and priritize VIP traffic as needed. Hw VIP Cmmunicatin Wrks: The fllwing represents a very basic, high level descriptin f hw Vice Carrier VIP cmmunicatins wrk. This is being prvided slely fr the purpse f helping t illustrate why the recmmendatins fr bth netwrk and device cnfiguratin are s imprtant when preparing yur netwrk fr Vice Carrier services. Registratin: With Vice Carrier, all services are SIP based and relay n SIP registratin and authenticatin. When a device is cnnected t yur netwrk it will make an attempt t send SIP registratin messages t the Vice Carrier clud. Assuming the netwrk is cnfigured prperly the registratin messages will be exchanged between the clud system and yur device(s) and registratin will be established. Messages will peridically be exchanged between the Vice Carrier clud and Page 3 f 15

4 yur SIP devices in rder t maintain this registratin status. It is these peridic messages that keep cnnectins pen thrugh yur ruter/firewall and allws fr cnsistent tw way cmmunicatin. If fr any reasn yur ruter/firewall clses this cnnectin between yur phne and the Vice Carrier clud, the phne will either becme unregistered r will be flagged as unreachable by the PBX. In either case Vice Carrier services will cease t functin prperly. It is fr this reasn that it is imperative that yu fllw the netwrk recmmendatins prvided in this dcument and cnfigure yur equipment with the apprpriate settings prvided. Call Set Up: In additin t establishing and maintaining Registratin status, SIP messages are als used t set up and tear dwn VIP calls. When call set up is perfrmed, bth ends acknwledge set up f the call and establish the apprpriate prts fr sending and receiving f the call media (RTP) traffic. Vice Calls: Once the call set up is cmplete the PBX and the device making r receiving the call will pass the actual call media back and frth as RTP traffic between the PBX and device. This is separate frm the SIP traffic and is why we need t priritize and manage bth SIP and RTP when preparing ur netwrk t apprpriately handle Vice Carrier VIP Bandwidth Utilizatin vs. Cncurrent Call Utilizatin Bandwidth Utilizatin All Vice Carrier services use the G.711 cdec fr RTP. This is essentially an uncmpressed vice cdec which utilizes 80Kbps f bandwidth in each directin (upstream and dwnstream) n a custmer netwrk during an active call. While there is always sme small amunt f SIP traffic n the netwrk that will be exchanged back and frth between phnes r ther devices at the custmer lcatin and the Vice Carrier clud, estimating the maximum number f cncurrent calls the custmer will have active and using the 80Kbps bandwidth utilizatin as shwn belw will help ensure that the ISP cnnectin the custmer intends t use t carry their Vice Carrier services will be sized prperly t effectively handle their VIP traffic. Example: custmer site will have up t 5 active calls at any given time 5 calls x 80Kbps in each directin = 400Kbps f upstream and dwnstream bandwidth required. Bandwidth is cnsumed fr all calls made frm a SIP device thrugh a system in the Vice Carrier clud. The 80Kbps (in each directin) described abve is per device invlved in a call and represents the packetized audi sent and received. Cncurrent Call Utilizatin As previusly discussed, Vice Carrier s service is smewhat unique in that it is priced based n cncurrent calls instead f by seat, user, r extensin. A cncurrent call is defined as a call t/frm smewhere n the Vice Carrier Netwrk t/frm smewhere utside f the Vice Carrier netwrk such as the PSTN r cellular netwrk. While all calls made frm a SIP device n Vice Carrier service will cnsume bandwidth n the lcal netwrk, nt all calls will cnsume cncurrent call paths r lines. It is imprtant t make this distinctin as it is integral in the planning fr netwrk capacity and fr cntracted line cunt as bth represent a cst t the end custmer. Page 4 f 15

5 The diagram abve illustrates the difference between bandwidth utilizatin and line (cncurrent call) utilizatin in the Vice Carrier envirnment. Here yu can see the difference between the bandwidth cnsumed fr an extensin t extensin call at the same lcatin when cmpared t the bandwidth cnsumed fr a call frm a single extensin t/frm the PSTN. Yu can als see hw an internal r extensin t extensin call des nt cnsume any cncurrent call paths as all traffic stays within the Vice Carrier netwrk while a call t r frm the PSTN will cnsume a cncurrent call path. Cnference Bridges and Line Utilizatin In additin t understanding when bandwidth is cnsumed n the lcal ISP link versus when a cncurrent call line is used in a nrmal call setting is imprtant but it is als imprtant t understand hw nn-standard call patterns such as cnference calling affect and are affected by the cncurrent call line cncept. As demnstrated abve, calls within the Vice Carrier netwrk d nt cnsume a cncurrent call path but any calls t/frm utside netwrks such as the PSTN will cnsume a call path fr each individual call. Vice Carrier hsted systems allw custmers t cnfigure cnference call bridges that are capable f supprting a large number f attendees. While the number f attendees can be cnfigured n the PBX fr a specific bridge, the ttal number f callers int a cnference bridge frm the PSTN is limited by the number f cncurrent call lines available fr that specific PBX. While mst custmers will cmbine bth internal and external users n cnference bridges, a cnference bridge will be limited t a maximum number f utside callers that is equal r less than their ttal number f cntracted lines. Because calls within the Vice Carrier PBX (extensin t extensin) d nt have an impact n cncurrent call Page 5 f 15

6 lines, there is effectively n limit n the number f internal callers dialing int a cnference bridge. Perfrmance Requirements By testing yur internet cnnectin yu will be able t determine (at least fr a given slice in time) the quality f varius netwrk measurements that are imprtant t ensuring VIP quality. Thse measurements and their descriptin are prvided belw. Packet Lss: Because VIP is simply vice cmmunicatin transprted in IP packets, minimizing (preferably eliminating) packet lss n the netwrk is a critical part f ensuring quality VIP cmmunicatin. When measuring netwrk quality yu shuld ideally lk fr 0.0% packet lss but VIP cmmunicatin will typically prvide acceptable quality n netwrks with up t 0.75% packet lss. Jitter: Jitter is the measurement f variatin in delay f packets. When running tests and lking fr acceptable jitter measurements fr VIP yu shuld lk fr Jitter measurements f less than 5ms in rder t sustain quality vice cmmunicatins. MOS: MOS stand fr Mean Opinin Scre and is a subjective scale fr estimating the quality f a particular VIP call based n the cmbinatin f factrs such as Jitter, Packet Lss, and Delay. While MOS is a subjective measurement, a netwrk shuld be able t maintain an MOS measurement f at least 3.8 r greater in rder t prvide acceptable quality VIP Yu can measure the quality f a given netwrk cnnectin at a specific slice in time by using the VIP readiness test n the Vice Carrier website via the link belw. By prviding this infrmatin t Vice Carrier as part f the initial setup guide when submitting an rder, yu give Vice Carrier supprt the ability t make recmmendatins and spt ptential prblem areas prir t attempting an install and ptentially running int an issue. Recmmended Netwrk Cmpnents Vice Carrier VIP will technically wrk n any internet cnnectin with sufficient bandwidth t supprt the number f calls required. There are a number f netwrking variables that, if set up prperly, can imprve the cnsistency and quality f VIP cmmunicatins. Internet Service Prvider Depending n the service prvider and service type, internet services can be delivered at synchrnus speeds (upstream and dwnstream speeds are the same) r asynchrnus (typically upstream speed is much slwer than dwnstream speed). While synchrnus high speed cnnectins are cst prhibitive in sme cases and in mst cases ISP ptins are limited, the fllwing is a list f ISP cnnectivity ptins in rder f preference fr Vice Carrier services. Page 6 f 15 1) Synchrnus, dedicated internet: This may include ptical fiber, metr Ethernet r ther high speed, dedicated circuits.

7 2) Business Cable 3) Residential (nn-business) Cable internet 4) Dedicated T-1 5) U-verse 6) DSL Ruter Yu will ntice that services like U-Verse and DSL are at the bttm f the preference list. While these services may deliver speeds cmparable t Cable and dedicated internet services, the quality, cnsistence, and stability f DSL-like services are typically nt as gd as the services higher n the list abve. In additin, sme versins f the equipment used t deliver these services, specifically the mdems, can interfere with SIP traffic withut special cnfiguratin. While there are many ptins available fr SOHO and small enterprise ruters tday, the gal is t find a ruter that prvides easy-t-cnfigure priritizatin fr VIP traffic and that des nt interfere with SIP messaging bth inbund and utbund. Vice carrier recmmends the Peplink series f ruters fr their ease f cnfiguratin, VIP friendly QOS algrithms and enhanced diagnstic capability. Belw are several recmmended Peplink ruter mdels based n the size f the installatin in questin as well as sme suggested ruter specificatins t adhere t shuld yu chse t use a different ruter manufacturer fr yu installatins. Peplink Ruter Recmmendatin Based n Size f Install Small Medium Large Up T 15 Users users 50+ users * Peplink Pepwave Surf SOHO Peplink Balance 210 Peplink Balance 305 Additinal infrmatin n specificatins fr each f these ruters as well as infrmatin n where t purchase can be fund n the Peplink website at General Ruter/Firewall Specificatins Based n Installatin Size (Vice and Data n Separate Netwrks) Vice Carrier realizes that custmer netwrking requirements may make it impssible t install the Vice Carrier recmmended Peplink ruter as specified abve. The infrmatin prvided belw gives general guidelines t fllw when selecting a ruter r firewall that is utside f the Vice Carrier recmmended Peplink ruters prvided abve. Keep in mind that nt all ruter/firewall vendrs prvide detailed specificatins fr their devices and these are simply intended t be guidelines t be fllwed in an effrt t ensure that the ruter being deplyed is capable f managing the SIP and RTP traffic that will be entering and leaving the lcal netwrk at the site. Small Medium Large Users Up T 15 Users users * Packets Per Secnd (Min) 2,500 10,000 15,000 Page 7 f 15

8 Cncurrent Sessins 1,000 2,500 10,000 RAM 64MB 128MB 512MB General Ruter/Firewall Specificatins Based n Installatin Size (Vice and Data n Same Netwrk) In situatins where bth vice and data are utilizing the same netwrk at the custmer site, the specificatins fr each device based n number f users must be increased t supprt the additinal data traffic and need fr QOS/priritizatin. The fllwing table prvides recmmended specificatins fr ruter/firewall that will supprt bth vice and data at a custmer lcatin. Small Medium Large Users Up T 15 Users users * Packets Per Secnd (Min) 15,000 IMIX 50,000 IMIX 75,000 IMIX Cncurrent Sessins 2,500 5,000 20,000 RAM 128MB 512MB 1GB Keep in mind that the recmmendatins prvided abve are meant t serve as guidelines fr apprpriately sizing netwrk hardware. Netwrk cnditins and ther factrs such as usage patterns and user behavir can impact netwrk quality. It is imprtant t understand the types f traffic n the netwrk and the hardware used (switches, hubs, cabling, etc.) in rder t guarantee the best chance fr a successful VIP installatin. Recmmended Peplink Specific Settings Set Up QOS t Priritze Vice Carrier VIP Under Advanced >> QOS >> Applicatin Add a Custm Applicatin called VC-SIP t priritize (High) UDP prts Add a Custm Applicatin called VC-RTP t priritize (High) UDP prts Under Advanced >> Service Passthrugh select Cmpatibility Mde fr SIP Set the items belw t enable easy remte access Under System >> Admin Security set Security t HTTPS Under System >> Admin Security set Web Admin Prt t 8080 Under System >> Admin Security set Web Admin Access t LAN/WAN Recmmended Ruter/Firewall Settings Enable QOS t Priritize VIP Traffic Priritize UDP prts fr SIP Priritize UDP prts 10,000-20,000 fr RTP Turn ff/disable SIP ALG (when present) Page 8 f 15

9 Turn ff/diable cnsistent NAT Transrmatins (when present) Turn ff/disable SIP Transfrmatins (when present) Set UDP Cnnectin inactivity timeut t 300 secnds (minimum) Disable Prt Scan Prtectin (when present) Disable DOS prtectin (when present) Switch Phnes While n specific make and mdel f switch is recmmended, it is imprtant t select a switch which prvides all f the required features based n the type and size f deplyment (see the architecture recmmendatins belw fr reference). If features such as VLANs, QOS, Pwer Over Ethernet, r Gigabit prts yu must select a switch r switches with thse capabilities and als ensure that the switch has high enugh thrughput t easily pass all vice and data n the LAN at wire speed. All Vice Carrier services are SIP based and as a result any unlcked SIP phne running standards based SIP firmware will wrk with Vice Carrier services. With that said, Vice Carrier sells a number f different SIP phnes. When SIP phnes are purchased thrugh Vice Carrier they are prvisined and tested by Vice Carrier s rder prcessing department befre being shipped t the custmer site. The majrity f Vice Carrier s installed base currently uses Yealink phnes and Vice Carrier has had years f successful implementatins f Yealink SIP phnes in netwrks f all shapes and sizes. In additin, Vice Carrier s relatinship with Yealink keep cst lw and supprt simple and cnvenient. Recmmended Architecture While all implementatins are different and nt every implementatin scenari allws fr changes t be made t the custmer netwrk, it is imprtant t cnsider, r at least be aware, f, sme best practices when it cmes t setting up a netwrk t supprt VIP cmmunicatins. At the cre f the recmmendatins belw is the cncept that the mre separate yu can keep vice and data the better ff yu will be in terms f guaranteed quality f VIP cmmunicatins. This becmes particularly imprtant as the size f the lcal LAN and the custmer netwrk grws. Belw we will tuch n methds fr keeping vice and data separate as well as sme imprtant cnfiguratin rules t fllw as the netwrk becmes mre cnverged. In additin we have highlighted architectural cmpnents that need t be adhered t independent f the architecture f the custmer s lcal netwrk. Netwrk Architecture and Cnfiguratin Cnstants 1) When bth an ISP mdem (cable, DSL, etc.) and ruter are used in the same netwrk, THE MODEM MUST BE IN BRIDGE MODE t avid NAT ccurring n bth the mdem and ruter. This will cause VIP prblems in almst all cases. If yu d nt have access t the ISP mdem in questin yu will need t cntact yur ISP. 2) It is always a gd idea t CONFIGURE QOS (specifically priritizatin fr VIP at the cnnectin t the ISP. Even in an ideal situatin where separate netwrks and separate ISP cnnectins are used fr vice and data, cnfiguring QOS at the upstream ruter will guarantee quality in the event that a nn-vice device is accidentally intrduced t the vice netwrk. The Page 9 f 15

10 methd yu use t cnfigure QOS will depend n the make and mdel f ruter yu are using. Sme general methds fr accmplishing this are as fllws. a. Give the highest pssible pririty t the fllwing i. UDP prts (fr SIP traffic) ii. UDP prts (fr RTP traffic) b. Priritize all traffic t and frm the Vice Carrier PBX using either IP r URL Nte: Using nly the IP address f the PBX can cause issues with QOS as the IP address f the Vice Carrier PBX can change ver time. c. Priritize traffic based n the netwrk segment r VLAN it is cming frm in situatins where yu have created separate vice and data netwrks (either physically r lgically) Physical Separatin f Vice and Data Netwrks The best way t ensure that VIP traffic desn t have t cmpete with, and ptentially lse t, traditinal data traffic is t make sure that VIP and data d nt ever crss the same wire r piece f equipment in the netwrk. By keeping VIP and data traffic separate yu remve any cmpetitin fr resurces and guarantee that VIP has unfettered access t all available resurces. Diagram 1 belw shws a basic example where tw cmpletely separate netwrks are created, ne netwrk fr vice and ne fr data. With this example separate ISP cnnectins are prvided which is an ideal situatin when deplying VIP services. The lcal ISP cnnectin is typically the biggest bttleneck in any netwrk and establishing a separate ISP cnnectin fr the vice netwrk guarantees that vice traffic has the greatest chance fr minimal delay, jitter, r packet lss t the ISP. Prviding a separate ISP cnnectin fr vice als helps yu right-size yur ISP cnnectin t apprpriately supprt yur expected VIP traffic. Diagram 1. Cmplete Physical Separatin f Vice and Data Diagram 2 shws a slight variatin t the netwrk described in Diagram 1 abve. With the netwrk shwn belw, there are still physically separate vice and data netwrks at layer2 n the custmer LAN but thse netwrks cnverge at layer 3 (IP layer) when they cnnect t the custmer ruter. This is great fr helping t avid cllisins and cngestin issues n the LAN but it des make cnfiguratin Page 10 f 15

11 f QOS/VIP priritizatin n the custmer ruter a critical cmpnent f success as bth vice and data will be cmpeting fr resurces n the ISP cnnectin. Diagram 2. Physical Separatin f Vice and Data n all Layer 2 (up t ruter) Lgical Separatin f Vice and Data Netwrks While physical separatin f vice and data n the custmer LAN is ideal when pssible, many custmer netwrks have existing wiring and LAN drps that can nt be recnfigured. In a scenari where vice and data must traverse the same physical cabling, netwrking equipment can be used t create a virtual segmentatin f vice and data. This is typically dne using the cncept f VLANS and require VLAN capable switches and in sme cases VLAN capable ruters. As previusly stated, the lcal ISP cnnectin is typically the biggest pint f cntentin in the netwrk and therefre it is ideal t prvide separate vice and data ISP cnnectins. Diagram 3 belw shws a scenari where dual ISP cnnectins have been installed but fr whatever reasn the ptin des nt exist t create separate vice and data LANs. As Diagram 3 shws, a VLAN capable switch is being used t create a lgical separatin between phne traffic and ther data. This can be dne even when user s cmputers are cnnected t the netwrk via the phnes r daisy chained. This lgical separatin makes it easy fr the switch t separate the vice and data traffic int separate physical uplinks as the traffic is passed up t the vice r data ruter as apprpriate. Page 11 f 15

12 Diagram 3. Lgical Separatin via VLAN n LAN, Physical Separatin at T ISP Diagram 4 belw shws an example f a netwrk where there is n ptin at either the LAN r WAN level t physically separate vice and data traffic. In this example VLANS are still used t lgically separate vice and data traffic until traffic is merged at the ruter and handed ff t the ISP. Because vice and data are traversing all f the same physical cmpnents in this example, the nly real advantages t using VLANs is; 1) yu have the ability t mre easily prvide QOS further ut in the LAN if the switches in the netwrk supprt QOS and 2) it may be easier t priritize and manage vice traffic since it will all be n a specific VLAN and can be cntrlled separately frm standard Data. In a netwrk scenari similar t the ne depicted in Diagram 4, ample bandwidth and prperly cnfigured QOS are critical factrs in maintaining vice quality. NOTE: Unless the apprpriate type f high quality ISP cnnectin and high end netwrking gear is being used, it is recmmended that sme level f physical separatin between vice and data (as shwn in diagrams 1 thrugh 3) is maintained fr all netwrks cntaining mre than 20 SIP devices. Diagram 4. Lgical Separatin f Vice and Data via VLANs t Ruter Physically and Lgically Cnverged Netwrks The least custmized type f netwrk cnfiguratin is a standard flat netwrk with n physical r lgical separatin f vice and data as shwn in Diagram 5 belw. It is nt advised that this type f netwrk cnfiguratin be used fr netwrks cntaining 20 r mre SIP devices. Bursty traffic patterns and ther unfreseen data usage can significantly impact vice traffic n the LAN as well as n the ISP cnnectin. Any time this type f netwrk cnfiguratin is used it is critical that QOS be prperly cnfigured n the custmer ruter, the ISP cnnectin be right-sized t adequately handle bth vice and data traffic, and that the ISP cnnectin be stable and cnsistent at any time when measured using the Vice Carrier netwrk test and metrics described in the Perfrmance Requirements sectin prvided earlier in this dcument. Page 12 f 15

13 Diagram 5. Physically and Lgically Cnverged Netwrks Netwrk Cnfiguratins t Avid The fllwing diagrams represent a cuple f very cmmn pssible netwrk cnfiguratins that need t be avided in netwrks where Vice Carrier services are deplyed. Diagram 6. Multiple Inline Ruters Prviding NAT The diagram abve shws a netwrk setup that is quite cmmn when smene attempts t extend the reach f a netwrk r prvide additinal prts t cnnect devices t. In this example, multiple ruters have been strung tgether and as a result there are wuld then be multiple devices in the netwrk handing ut IP addresses via DHCP and multiple devices prviding NAT between netwrks. This will almst always cause issues with VIP and at best will cause unpredictable and unreliable results. Whenever an aggregatin device is needed t prvide additinal uplink prts int a netwrk r t extend the reach f a netwrk, a switch and nt a ruter shuld be used. Keep in mind that if the mdem is nt set t bridge mde in this type f netwrk cnfiguratin it will be acting as a ruter and will cause the same type f issues as having tw r mre standard ruter/firewalls in line. Page 13 f 15

14 Diagram 7. Separate Ruters Prviding Uplink t Same ISP Diagram 7 depicts a scenari where there may be several separate netwrks using the same ISP cnnectin. It may seem lgical t cnnect each netwrk directly int the ISP mdem r uplink device as shwn abve. When a netwrk is cnfigured like this it is likely that issues will arise with vice quality because there is n lnger a single device that all traffic passes thrugh that is capable and cnfigured t priritize vice traffic ver regular data traffic. While physical separatin f vice and data is ideal, if the same ISP is ging t be used fr bth types f traffic they shuld ideally be merged thrugh a QOS capable ruter that has the capacity t handle and apprpriately priritize all traffic. Basic Trubleshting If yu have fllwed all f the guidelines and cnfiguratin rules cvered in the sectins abve, yur netwrk shuld be in set up and ready fr the installatin and peratin f Vice Carrier services. Shuld yu have issues with installatin r nging peratin the fllwing are sme basic steps t fllw t try and determine what might be causing and then reslve the issues yu are experiencing. Check the registratin status f the device. As previusly described, all Vice Carrier services are SIP registratin based. One f the mst elementary building blcks f yur Vice Carrier service is the device registratin. Device registratin can be cnfirmed in the fllwing ways. 1) Check the interface f the phne r device in questin and cnfirm that it is shwing as Registered 2) Lg in t the Vice Carrier PBX and check the SIP Peer status under Tls >> SIP Inf >> Peers Typical causes f failed registratins are miscnfigured SIP device (phne, ATA, custmer PBX in the case f SIP trunk) r lcal netwrk issue preventing the phne frm accessing the netwrk and sending SIP registratin requests t the PBX Cnfirm Device Reachability (Frm the Standpint f the PBX) Page 14 f 15

15 There are certain circumstances where yu may find that devices will register but then intermittent issues arise with the phne nt appearing nline r with inbund calls (r transfers) ging straight t vic instead f ringing the phne. In mst cases this is caused by the PBXs inability t reach the phne r device in questin. This can be cnfirmed by lking at the Peer infrmatin n the Vice Carrier PBX. If yu lg int the Vice Carrier PBX and g t Tls >> SIP Inf >> Peers yu shuld see that all extensins that shuld be peratinal will have OK n the same line as the extensin number in the peer statement. If a phne r device is nt reachable yu will see the wrd UNREACHABLE in all caps n the same line as the extensin in questin. Reachability issues are 99.99% f the time caused by a cnfiguratin issue n the end custmer ruter r LAN and are the result f the ruter/firewall clsing the sessin/cnnectin between the PBX and the phne. In rder t reslve this issue make sure that yu have dne the fllwing 3 things. 1) Cnfigure QOS n the ruter t mimize delay in respnses frm the phne t the PBX 2) Cnfigure the ruter with the settings specified in the Recmmended Ruter/Firewall Settings sectin earlier in this dcument 3) Make sure yu d nt have multiple devices prviding NAT in the path between the phne and the Vice Carrier clud as shwn in Diagram 6 abve. Vice Carrier Supprt can check the PBX lgs if needed t determine if devices have been intermittently ging UNREACHABLE ver the hur perid prir t yu reprting the issue. Test An Extensin r Device frm Anther Lcatin If yu are cnsistently having issues with devices at a particular site and are trying t islate the issue, it is always helpful t cnfigure an extensin n the PBX that can be used fr testing and either cnfigure a device at anther lcatin t see if it exhibits the same symptms r take ne f the devices that is having an issue at a particular lcatin and mve it t anther lcatin n a different ruter and ISP cnnectin in an attempt t islate whether the issue is with the netwrk, the ISP, the ruter, r the phne itself. Page 15 f 15