#burstable

前一篇「在 AWS 上面的 OpenVPN Server 效能」最後的問題就是 EC2 instance 本身的網路效能，畢竟是公司要用的，還是實際測一下數字，之後有人接手的時候也比較清楚是怎麼選這個大小的… 這邊拿的是 AWS 的 ap-southeast-1 (Singapore) 的 EC2 測試，直接在同一個 subnet 裡面開兩台一樣的機器跑 iperf 測試。 機器開機後會先跑這串指令 (除了安裝 iperf 的指令，其他的是出自我自己 wiki 上的 Ubuntu 這頁)，然後再重開機： sudo fallocate -l 512M /swapfile; sudo chmod 600 /swapfile; sudo mkswap /swapfile; sudo swapon /swapfile; echo '/swapfile none swap sw 0 0' |…

Today, XO unveiled a new SIP trunking service – XO Enterprise SIP, targeted specifically at large, multi-site enterprises (see press release here). XO is one of the leaders in VoIP access services, including basic VoIP access lines, VoIP trunks connecting with TDM customer premise equipment (CPE), as well as SIP trunks for IP telephony platforms. So far, XO’s converged services have been most successful among SMBs, and so have been most other VoIP/SIP trunking services offered by its competitors. The new service delivers specific benefits to large, geographically dispersed businesses and is likely to boost XO’s penetration in that segment.  

One of the key elements of the new offering is the ability for business customers to pool trunks from across multiple sites into one or several primary locations and thus reduce trunking costs as well as potentially CPE costs, if they choose to eliminate some of their branch-office call control and feature platforms. This capability also enables businesses to streamline relationships with local voice service providers. Another key feature of XO Enterprise SIP is its inherent business continuity capability to provide automatic failover from one Enterprise SIP connection to another, ensuring redundant paths to the PSTN in the event that one of the primary SIP connections is unavailable. 

Businesses can send voice traffic to the SIP trunking sites either over their own private data networks, a third-party VPN, or using XO’s MPLS VPN service. The availability of these alternatives makes XO’s service one of the most flexible SIP trunking solutions on the market today. However, customers should be aware of the various implications of the different implementation options. In the first two scenarios, XO’s demarcation point is at the trunking site(s), which limits its ability to control the voice network beyond that point. It states, however, that it will still strive to assist its customers with any potential issues related to the private data network and its ability to support real-time communications. If a customer chooses to deploy XO’s MPLS VPN service, on the other hand, XO can assure the quality of service all the way to the switching platforms on the customer’s premises. XO can also offer managed router or SBC (session border controller) services to customers that choose to take advantage of that option.  

A second key element in the new offering is the ability for XO customers to dynamically share voice trunks across multiple sites and “burst above capacity” when needed. They can configure communications capacity across their entire network and then the various locations can “borrow” or “lend” unused trunk capacity amongst each other. This feature is particularly useful to businesses with locations in different time zones or otherwise varying peaks and lows in voice capacity utilization. A similar capability was first introduced by Verizon as Burstable Enterprise Shared Trunks (BEST) and has proven quite successful among retail businesses. XO states that it differentiates itself by offering superior levels of service management as well as redundancy at all customer locations. Further, XO can route traffic across sites, as well as to and from other carrier networks in case of a service failure. Finally, it claims advanced encryption capabilities as an additional feature option. 

Eventually, businesses using XO’s Enterprise SIP trunking service can choose to eliminate telephony platforms at their branch locations and use the features on the IP telephony platform deployed at headquarters (or another main site). That scenario provides some further cost saving benefits. 

XO’s Enterprise SIP service rounds up a portfolio of VoIP services including XO IP Flex, targeted at customers with existing TDM equipment; XO IP Flex with VPN; XO SIP, targeted at customers with IP telephony platforms; and XO One iPBX, a managed, premise-based IP telephony solution. 

Similar to other VoIP access/trunking services offered by XO and its competitors, the new service includes unlimited local calling and features such as Local Directory Assistance, Local Operator Services and Directory Listings at additional charges. Site-to-site calling is free as it is managed by the customer’s own data network. One 800-number is included free of charge. Verified Account Codes, Compression, Additional DID's, Additional toll free numbers, Virtual Telephone Numbers, and Automatic Call Routing (ACR) are available for an additional charge. Customers are required to select an XO long-distance calling plan.  

VoIP access and SIP trunking services have finally gained traction after several years of limited market acceptance. Growing IP telephony penetration is a major driver along with rapidly improving interoperability between service provider SIP trunking services and vendor IP telephony platforms. XO itself confirms that, a couple of years ago, its SIP trunking interoperability was limited to Cisco and Avaya platforms, whereas today, it can support a large variety of IP telephony solutions including those offered by Digium, Fonality, NEC, Toshiba, etc. Another key factor driving VoIP access and SIP trunking services adoption at times of a global recession is the economies that businesses can realize by converging access lines and using VoIP for long-distance calling.  

Going forward, businesses will continue to seek opportunities to consolidate their infrastructure and leverage advanced technologies for both cost savings and productivity benefits. On the premise, architectures such as Avaya’s Aura are enabling businesses to pool trunks, use abbreviated dial plans across multiple sites, and propagate features across geographically dispersed users in multi-vendor call control environments regardless of the individual feature servers at each location. Service providers such as XO can add further value by ensuring that businesses have access to E911 services as they consolidate trunks and voice traffic. This is one of the biggest challenges with emerging IP telephony and UC architectures.  

It is important to note that certain limitations apply to E911 services with both XO’s and other providers’ VoIP services. It is critical that business decision makers take these factors into consideration and review all related literature when choosing a VoIP vendor and/or service provider. Customers should also keep in mind that, in most cases, some additional CPE such as VoIP gateways and/or SBCs will be needed in order to successfully connect XO’s services to existing telephony platforms. Therefore, customers will need to investigate all related interoperability and certification issues. Further, businesses should consider service providers’ geographical coverage in selecting a SIP trunking partner. XO offers services in all 50 states and in 2,700 cities, which is a considerable advantage in delivering services to geographically dispersed businesses.