Comprehensive Understanding of PPP Multilink

In network protocols, PPP is a basis. In the previous article, we also introduced the concept and authentication content of PPP. I believe you have some experience. Here we will focus on the specific content of PPP Multilink. First, let's see how PPP Multilink works.

How does PPP Multilink work?

PPP Multilink divides a single PPP connection into two independent physical links and reassembles them in the correct order. To achieve this, you must have a hardware device or software program that complies with the MP protocol at both ends of the link.

MP is used to execute the above functions:

· The Source MP receives the data packet

· Cut them into fragments (optional)

· Determine the next available Link

· Add a PPP Multilink header containing sequence numbers and other information

· Forward data packets or fragments to available links

· The receiver's MP receives data packets or data packet fragments.

· Remove the MP Header

· Combine fragments into a complete package

· Forward data packets to the corresponding IP Address

As a result, no matter how different these links are in terms of capacity or the amount of bandwidth available to you, You can smoothly allocate traffic on the available links.

What are the limits of PPP Multilink?

Since PPP Multilink uses the binding technology, all bound links start and end on the same pair of endpoints, allowing them to separate and reorganize data streams. Therefore, both ends must support the PPP Multilink protocol.

Simply put, this means that to use Multilink PPP, your ISP must have hardware or software that supports Multilink PPP for the access type you are using and provide this service to tenants. Not all access types are supported. You may use MP on a special modem, but your ISP may not have the corresponding hardware. The vast majority of ISDN support ISP binding to two B channels to provide MP. Similarly, most of them also provide support for binding V.90 modem. If you want to bind other access types such as DSL, it is also feasible, but it must be built on a very expensive hardware routing solution that does not cover most end users, and only a few ISPs provide support.

As far as we know, as of this article, most ISPs have not provided support for PPP Multilink for access types other than ISDN.

What are the advantages of PPP Multilink?

The use of single-connection protocols will benefit from transparent multi-Link

The main advantage of PPP Multilink is that it is a public standard, so at least theoretically providing cross-vendor collaboration capabilities and compatibility. It is even advantageous for a single TCP/IP connection. For example, an FTP download can benefit from multiple links. If you download an object through a PPP Multilink connection bound to two links, the download speed will be twice faster. Both the FTP client and the server do not know that there is a multi-link connection in the middle. In short, because PPP Multilink is a transparent Protocol, any protocol that uses a single connection between the host and the client, such as terminal simulation, will benefit from the bandwidth integration provided by multiple links.

What is a combined Connection Teaming )?

PPP Multilink and Connection Teaming

Unlike PPP Multilink, the Connection Teaming link is not terminated on a pair of endpoints.

Connection Teaming is a form of bandwidth integration without binding links. It uses standard protocols to establish and maintain separate TCP/IP dialogs along multiple links. A Connection Teaming server connected to the LAN and the Internet receives a request from the LAN client and forwards the request to the next available Connection. The LAN browser and other clients do not need to know which connection forwards their requests to the Internet. Unlike the bound link, a single request is not separated by multiple links and then reorganized. In Connection Teaming, each request must follow one of the available data paths.

How does Connection Teaming work?

Connection Teaming significantly improves the effective throughput

The Connection Teaming server is located inside the LAN and is an integral part of the routing software between the user and the Internet. When a TCP session is opened, the server uses a low-traffic link. Most HTTP, FTP, or other TCP sessions opened by LAN computers are allocated to all available connections in this way. The result is that the Internet traffic is allocated to multiple available links, increasing the effective throughput.

What are the restrictions on Connection Teaming?

The most basic limitation of Connection Teaming comes from the fact that it does not split a single request. When a single user downloads a large file, it will not experience any benefits of Connection Teaming. Some Teaming solutions allow FTP to carry packets on multiple links. However, in any case, it cannot be used to pass a large image through HTTP Connection Teaming.

What are the advantages of Connection Teaming?

Connection Teaming allows the combination of cable modem, DSL, and legacy modem

Connection Teaming can use different Connection technologies. It makes it possible to merge the new modem and the old modem you are using. You can also combine the analog modem and DSL, or the cable modem.

When multiple TCP/IP connections occur simultaneously, Connection Teaming can share the load

Connection Teaming is an effective method to share the load whenever multiple TCP/IP addresses occur simultaneously. For example, if a user establishes an FTP download connection, it can only use one of the links, leaving other available links for other users to connect.

Connection Teaming can enable additional connections as needed

Connection Teaming can enable additional connections as needed, for example, when the existing bandwidth saturation reaches 80%, or when a special route is applied.

Each link works like a separate Internet connection.

Connection teaming allows sub-links to connect to different Internet access points or different ISPs, so it is unnecessary to find the corresponding ISP. Each link works as a separate, independent Internet connection. Therefore, the service provider at the upper level does not need to know that your system is using teaming, nor need any special protocols or leasing options.

Is Connection Teaming useful to a single Internet user?

Pass individual page elements through a combined connection

Without a doubt, a Web page consists of an independent graphic unit. Each such unit involves a separate HTTP request. Each request can be transmitted through different links. Therefore, even when a single user browses the Web, the real performance increases.

What is the benchmark?

PPP Multilink is transparent and seamless. It splits a single packet into fragments to adapt to the largest transmission unit. If you plan to use only analog modem or ISDN for a single user and frequently download large files, PPP Multilink will give you the best results. In this case, it is the first choice.

In another case, if you want to mix and match the Connection type, or if you already have multiple network users and want to restrict FTP from using a single channel, Connection Teaming may be more suitable.