The world of proxies are full of lots of new and developing technologies. Unfortunately in many senses the technology moves so fast that the language behind these is often lagging behind. What tends to happen is that lots of confusing and divergent descriptions exist about the latest development. Someone will use one definition and spread it until it become somewhat widely accepted yet these terms are often misleading or just completely wrong.

Here’s some brief introductions from our friends below – (click image to check out their proxy range and bonuses)

So Rotating Dedicated Proxies ?

So let’s break this down into two simple components, firstly dedicated proxies – which are those only used by a single person or organisation. They are in fact dedicated to this one purpose, in all other aspects a dedicated proxy will still hide your IP and protect your privacy. Ultimately it will be even more secure as no-one else will be permitted to use it. You may also come across the term semi-dedicated proxy in which in most contexts merely means the proxy (and it’s IPs) are shared between a small group of people or businesses.

These will always be some form of paid proxies and indeed they are likely to be much more expensive than standard shared proxies. You will also find them broken down or specializing in other areas such as for use with certain social platforms or even UK rotating proxies. These will be standard proxies but with UK IPs.

So what About the Rotating Proxies Bit?

So again, the phrase can be open to different interpretations (also known as backconnect proxies) but generally the ‘rotation’ refers to the rotating IP addresses it uses. Instead of a standard proxy which generally may have a couple of network cards with an IP address or two assigned to both, rotating proxies have many more. The rotating proxy will select a single IP address from a large pool of addresses then switch this at a specified period. This IP rotation may occur after each connection, every unique HTTP request or simply after a specified time period.

The idea is that allowing the proxy servers to control the IP address allocation means that it can ensure that it rotates through an IP address pool efficiently. That is avoiding concurrent connections, where two people use the same address at the same time. It also makes sure that the addresses are used evenly and more efficiently which ultimately is reflected in the price.

There are loads of others, here’s a brief description of caching proxies which are more commonly used in busy corporate networks.

Without caching, the WWW would become a victim of its own success. As Web popularity grows, so does the number of clients accessing popular Web servers, and so does the network bandwidth required to connect clients to servers. Trying to scale network and server bandwidth to keep up with client demand is an expensive strategy.

An alternative is caching. Caching effectively migrates copies of popular documents from servers closer to clients. Web client users see shorter delays when requesting a URL. Network managers see less traffic. Web servers see lower request rates.

A cache may be used on any of the following: a per-client basis, within networks used by the Web, or or on web servers. We study the second alternative, known as a “proxy server” or “proxy gateway” with the ability to cache documents. We use the term “caching proxy” for short.

A caching proxy has a difficult job. First, its arrival traffic is the union of the URL requests of many clients. For a caching proxy to have a cache hit, the same document must either be requested by the same user two or more times, or two different users must request the same document. Second, a caching proxy often functions as a second (or higher) level cache, getting only the misses left over from Web clients that use a per-client cache (e.g., Mosaic and Netscape). The misses passed to the proxy-server from the client usually do not contain a document requested twice by the same user. The caching proxy is therefore, left to cache documents requested by two or more users. This reduces the fraction of requests that the proxy can satisfy from its cache, known as the hit rate.

How effective could a caching proxy ever be? To answer this, we first examine how much inherent duplication there is in the URLs arriving at a caching proxy. We simulate a proxy server with an infinite disk area, so that the proxy contains, forever, every document ever accessed. This gives an upper bound on the hit rate that a real caching proxy could ever achieve. The input to the simulation is traces of all URL accesses during one semester of three different workloads from a university community. Overall we observe a 30%-50% hit rate. We also examine the maximum disk area required for there to be no document replacement. We then consider the case of finite disk areas, in which replacement must occur, and compare the hit rate and cache size resulting from three replacement policies: least recently used (LRU) and two variations of LRU. LRU is shown to have an inherent defect that becomes more pronounced as the frequency of replacements rises. Finally, we use the best replacement policy and examine the effect on hit rate and cache size of restricting what document sizes to cache and whether to cache only certain document sizes, document types, or URL domains.

Source: https://www.w3.org/Conferences/WWW4/Papers/155/

Rotating Proxies Aren’t Always What You Need

One of the problems that many people find with rotating proxies is that your IP address changes automatically. This sometimes doesn’t matter, but for many tasks it’s extremely important. For example one of the most common uses of a proxy service particularly residential ones is to impersonate an ordinary home user. These residential proxies are actually very difficult to create,  basically because residential IPs are much harder to get than those assigned to datacenter proxies.  You may be running loads of social media accounts, buying concert tickets for profit or simply posting adverts on Craigslist. The key factor here is to appear like an ordinary home user in order to run multiple accounts and avoid detection and so you must use a residential proxy.   If you’re using for a specific purpose it’s usually best to ask for proxies dedicated to that platform too.

Yet the obvious issue is that ordinary users don’t switch IP addresses every few minutes. Indeed most people using the internet at home have a static residential IP address which rarely ever changes.  Suddenly that rotating IP becomes a negative factor, removing the benefit of using residential IPs. Indeed rotating residential proxies are actually easier to find than those which don’t use IP rotation.  Proxies rotating between addresses allow a more efficient use cases but they’re not always ideal for specific purposes.

This can be a problem for many tasks specifically those which require longer persistent connections.  If your IP keeps rotating during an e-commerce transaction between locations all over the world then you’re going to get flagged as suspicious very quickly !

So although, rotating proxies keep the costs down by enabling firms to use their resources efficiently – they’re sometimes not suitable.  Fortunately there are a few companies who do provide static addresses.  Unfortunately not that many and some allocated these proxies dedicated to specific tasks/platforms.  One of the companies is called RotatingProxies who have some static IPs but the biggest range are probably offered by Smart Proxies particularly if you need to geo-target.

Not the cheapest company, yet all the decent proxy services rarely are. They do have plenty of residential addresses though, offer the ability to geo-target to the city level in the USA plus they can stop your IP address rotating automatically. They’re particularly popular with SEO firms and people who want to leverage Craigslist adverts for their products and services.  If you want a relatively risk free experience then it’s often best to choose one of the premium providers.  Some backconnect proxies on very cheap providers are little more than gateways to bot networks.