Quintum vs Cisco This is the first version of the document. I do not pretend that everything inside this document is true. I am looking for any suggestions (based on facts, I won't reply to any "flame" e-mail) and will post them here if they are correct. The name of the document sounds sort of misleading, but not think that I am a Quintum biased person. I can work with Quintum as good as with Cisco (or Asterisk, Audiocodes and AddPac). Feel free to contact me at tgeorgiev@is-bg.net or lv_tokata@yahoo.com MSN: teodor_bg@hotmail.com 1. DSP cards. On Quintum you definitely know that you can make "so many" calls with a particular gateway model. In DX2030 you know that 30 simultaneous calls can be accomplished, no matter the codec used. At Cisco, you have to go through the unpleasant procedure of calculating how many calls you can do with each codec, depending on Codec complexity. In Cisco, codecs are split into medium- and high-complexity ones. High-complexity codecs (G723, gG729, G729-AnnexB, T38 fax) occupy 1/2 (half) DSP per call on some DSP cards, whilst medium-complexity codecs occupy 1/4 of the DSP per call. Not all the codecs are supported on all of the platforms. In example, the 5350 series do NOT support the G729A codec. For a good descripton of this nightmare, see the following URL: http://www.cisco.com/warp/public/788/voip/codec_complexity.html 2. Cisco offers you to participate in a very ugly game called: "Guess the correct IOS". Each IOS has different feature sets. Lets say you find an IOS for your 2600 router. You need prepaid calling card support, H323 support, Radius support, R2D signalling support. It has to be a new one, because the older ones are "equipped" with the ICMP DoS vulnerbility. OK, you find some 12.3 IOS, but it supports ISDN PRI, not CAS (R2). Lets find another one... We find another one, but it supports the version 1 of the TCL IVR API, and your app_debitcard script is version 2. Anyway, we find another one, it has all the features you need. But its size is 17MB and your flash memory is only 16. Bad luck... Or you need SIP. Pretty fine, you download an IOS, it has SIP support, but you can not authenticate with an username+password against your SIP registrar/proxy server. Ohhhhhhhh, did I forget to mention that the Cisco IOS images are not freely available for download. You must possess a CCO account in order to have access to the Cisco IOS database + the IOS locator/configurator. Buying a second-hand / refurbished Cisco router/gateway with a valid legal IOS does not give you any right over the IOS. You must purchase an IOS from an official Cisco dealer. Shortly said - the situation with the Cisco IOS images can be called "a complete mess". Newer IOS does not mean a "better IOS". In comparison to that, at Quintum, the firmware images are freely available for download, they contain all the features you need. And in 99% of the cases, the newest firmware image is the best one - with the most features added and bugs fixed. A firmware image on a digital Quintum Tenor gateway contains support both for ISDN PRI and R2 CAS. You just reconfigure the Layer 2 protocol and voila! 3. Many Internet Providers (specially the state owned ones in the third-world countries - Africa, Middle East, Asia) block the H323 and SIP call-signalling ports (TCP 1720 and TCP 5060) in order to prohibit the usage of VoIP. With Quintum you can change both the incoming and outgoing call signalling port. So to say, you can change the port at which Quintum listens and accepts incoming calls, and you can change the call signalling port for the outgoing call requests. Thus, you can circumvent the VoIP-restrictive firewalls. In Cisco that is completely not possible (as far as I know). One thing you can do is a tunell (IPIP, GRE and etc) between the POPs. With the newest Quintum firmware you can also change the UDP port range (for voice). This is completely not possible with Cisco. 4. Quintum digital ports support both E1 and T1 (software-configured from the CLI). With Cisco, you see a very cheap refurbished gateway at Ebay, but you can't buy it, because it is equipped with T1 cards, and you are outside of North America, working at E1. 5. Quintum Tenor Gateways can be configured via their Tenor Configuration Manager, a very nice and powerful GUI. It is free of charge (unlike the Cisco buggy and ugly HTTP interface, or expensive third-party products like the one of Telcony) and can be used even when the Quintum gateway is behind a NAT with a private IP (in this case the gateway is the one, who initiates the connection to the Tenor Configuration Manager). 6. The debug output, produced by Quintum is far better/easy to "read" and understand, than the one of Cisco. Specially the CH (Channel Handler, the mostly used) debug and the Q.931 PRI / R2. This helps greatly in troubleshooting. 7. Quintum Tenor gateways have a built-in gatekeeper/border element. It allowes to register H323 endpoints with it (via RRQ) and at the same time it allows the Quintum gateway to interact with H323 "elements" in all the three possible ways --> RAS (RRQ/ARQ), direct H.225 signalling (GW-to-GW), gatekeeper-to-gatekeeper routing (LRQ, remote zone routing). The Cisco voice gateways can either register to a gatekeeper, or to use the direct H225 signalling (session target ipv4). They can not "speak" to gatekeepers via LRQ, neither they can "play" a gatekeeper. 8. Quintum have an unique feature called "relay bypass". Lets suppose that a DX2030 Quintum Tenor (2 E1 ports, 30 simult calls) is sitting between the PSTN network and a PBX - an usual solution for office interconnection. The first E1 is connected to the PBX and the second - to the PSTN. All the traffic is passing through the Quintum. Suddenly, due to a hardware failure, configuration mistake, power outage or whatever, Quintum is not able to route the call. A relay will "bridge" the two E1 ports, thus ensuring a transparently passage of the traffic between the PBX and the PSTN. 9. Quintum's H323 stack is a stable one, posseses excellent interopability and is highly configurable through the CLI/GUI. The official H323 tests show that Quintum Tenor gateways posses the best H245 tunelling support & interopability. 10. A configurable "asnwer tone". Quintum will play a preconfigured DTMF tone (C) once a call is connected. This is a useful feature for call-shops in example, where this will trigger the billing LCD display in the cabine. ============================================================================================================================ Quintum disadvantages: 1. Odd routing logic. Based not on the longest match, but on the route type. Each type of route (PSTN, PBX, IP) has a priority. If you have a 0* route through the "PBX" trunk group (LCRG), and a 001* route via PSTN (a TCRG group), Quintum will try first to go through the PBX route, despite the longest match. Yes, this is really odd, but if you get used to it, you will be able to create a really complex and powerful call routing scheme. 2. Basic IVR system. The IVR in Quintum is a built-in one. In Cisco, you can write your own custom IVR scripts with the help of their TCL engine. However, Quintum are on their way to develop a highly-customiseable IVR engine. 3. Quintum is merely a voice gateway. It is not a router, can not do bandwidth management, OSPF, BGP and etc. It can not be used as a dial-up RAS at the same time. It can not serve as a T37 on-ramp / off-ramp gateway. 4. Poor number rewriting engine. In comparison to Cisco's SED-style rewriting engine, the one of Quintum is not a match at all. 5. Cisco have much better support from the IT community. There are too many places (mailing-lists, forums) where you can get valuable help on your problem. On the Cisco NetPro forum or the cisco-voip mailing list, CCIE and Cisco engineers will give you a helping hand in troubleshooting an odd problem. Cisco is greatly documented. With Quintum you are on your own. There are no forums/mailing-list where you can get any serious help. But you can get a support contract "right from the source" on a modest price. Bear in mind that Quintum is just gaining speed. There are already some forums, where one can get his Quintum questions answered. The Quintum community is now large enough ;) 6. The QSIG support is only for basic call setup, it does not support the QSIG facilities. 7. Unlike Cisco, Quintum can not work simultaneously with SIP and H323. Indeed, Quintum voice gateways are able to receive calls both in H.323 and SIP, but the outgoing calls are to be statically set up to either H.323 or SIP. However, with the Quintum call routing you can do both SIP/H323. 8. In Quintum you can not "attach" different Radius servers to the trunk groups (TCRG,LCRG,IPRG), as you can do this in Cisco 9. There is RO/RW SNMP community in Quintum. Not a big deal, but... 10. Another (not so important though) disadvantage is that Quintum does not support MGCP. 11. Quintum H323 stack (at the time of writing this document) is still version 3. 12. Quintum is not able to simulate a call (useful in debugging from remote locations). There is no copy of the Cisco "csim start" command in Quintum. =============================================================================================================================== I have got some e-mails from Asterisk fans recommending me a solution of Asterisk + Digium cards and bragging how wonderful it is and how cheap in comparison to all other gateway vendors it is. Well, guys, I have some fair good amount of experience with Asterisk as well. I also like Asterisk a lot, but everything has a place where it fits at its best. Lets really see how cheap could be Asterisk. Lets suppose, we need to build a voice gateway with 4 BRI ports. Lets start with Asterisk: * The cheapest 4 BRI card that could be found on the market goes for not less than $600. * $80 will cost the G729 codec license from Digium for 8 channels. * Not less than $250 will cost a good PC (without a screen) which we would use for the Asterisk. * Now, if you are a Linux and VoIP guru - pretty well. You will install Linux, then Asterisk, then drivers for the ISDN BRI card and that is. What if you are not? And even if you are, time costs money. Time is expensive. I would estimate a price of not less than $300 for all the job. So, finally the price goes to $1300. At the same time, A Quintum BX408 costs about $1600 (depends on which part of the world you are going to purchase it from). The financial outcome is that we are saving apprx $300. Lets see now the pro's and con's of this solution: Advantages: 1. Cheaper price 2. The system can be used for many other things - router, firewall, billing, syslog'ing and etc Disadvantages: 1. The H.323 support of Asterisk is not reliable at all. It leads to bugs (like one-way audio) and crashes. I have seen systems where after the 6-7th simultaneous call, the whole Asterisk crashes. Recently I found a security bug in the chan-h323 which leads to remote DoS (the whole Asterisk system crashes). 2. Lack of G.723 codec support 3. Lack of QSIG support 4. Requires quite more technical knowledge and experience to maintain the system. One should possess knowledge also in Linux administration to upgrade the kernel (in case of a critical bug), firewall the system and etc. So, in general - Asterisk is suitable for "hackers" (no, not these who break into other´s systems), with a lot of experience in telecom, networking, Linux systems and programming/scripting. But for the average IT engineer - it is not a good idea at all.