Tag: QoS

Introduction

I am reviewing the Western Digital MyNet 8-port Gigabit Ethernet Switch which is an Ethernet switch that is positioned for use as the “central” switch in a wired-for-Ethernet house. This device, which is part of Western Digital’s entry into network infrastructure hardware also has a port-based quality-of-service setup in order to prioritise traffic serving multimedia or IP-telephony devices.

Price: AUD$99.99

LAN Connectivity

The device itself

Setup

Front indicator lights – orange for 10/100 Ethernet connection and green for Gigabit Ethernet connection

The WD MyNet Switch has a setup routine that is typical for any unmanaged Gigabit Ethernet switch that is pitched at small network use. This is where you simply plug the Ethernet devices in to the switch, then connect it to the power.

But this switch implements a port-based quality-of-service setup with dark-green ports for high-priority traffic, light-green for medium-priority traffic and orange for best-effort traffic. This is to assure that VoIP and audio/video streaming is passed through without any glitches.

In the product documentation, Western Digital recommends that a NAS full of multimedia files or PVR acting as a DLNA Media Server be plugged in to a light-green port and a network media device is plugged in to the dark-green port. This would be of best effect if you were viewing content held on the server without glitches caused by email checks or Web-surfing.

Functionality

Rear Gigabit-Ethernet connections – dark-green for highest priority, green for high priority, orange for best-effort and connection to other LAN segments

Compared to a lot of Ethernet switches, the Western Digital MyNet Switch has the status lights located up front rather than the lights being next to the Ethernet sockets. This may be a benefit if you have the unit on a desk or mount it to the wall using the keyhole slots and you have the sockets located on the opposite side. Here, you can still troubleshoot the network connectivity and link speed without having to swivel the unit around.

A test that I do for Gigabit Ethernet switches is to find out whether they do work properly with UPnP and Bonjour. This test has become important for me with network hardware because I once bought a “Chinese special” Gigabit Ethernet switch at a computer market and found that it didn’t pass through any of the broadcast data that was required for essential UPnP functionality. Then I replaced it with a D-Link Gigabit Ethernet switch and found that this one worked properly with these devices.

Here, I connected it between a UPnP-enabled printer and my computer then power-cycle the printer to see whether the printer presents itself as a UPnP device to Windows 7. The printer had presented itself properly to Windows 7 as a UPnP device. Subsequently I had plugged my WD MyBook World Edition network-attached storage device in to this switch and kept an eye on the availability of its DLNA server from behind the switch and it was still available.

There is inherent support for quality-of-service prioritising but this is a port-based affair. Here certain ports are coloured in distinct colours for applications where high QoS is desired with some marked as “Low” preferred for LAN, off-ramp and router uplinks. You may have to do things like plug the smart TV or network media player in to the green ports while you plug the regular computer that does a lot of Web traffic in to the orange ports.

Limitations and Points Of Improvement

There is no quality-of-service pass-through or trunking available with this switch for use with LAN connections. This can be an annoyance if you are trying to prioritise multimedia data across the whole network and is due to the industry not implementing standards for assuring quality-of-service across a logical network.

Conclusion

I would recommend the Western Digital MyNet Gigabit Ethernet Switch as a “central” switch for a small Ethernet network where quality of service for multimedia applications is considered very important such as most home networks. It would also keep the home network “futureproof” for IP-based telephony if the telephony equipment is connected to a “green” socket.

Article

Engineers rebuild HTTP as a faster Web foundation | Deep Tech – CNET News

My Comments

HTTP has been the standard transport protocol since the dawn of the World Wide Web and effectively became the backbone for most file transfer and streaming activities of the modern Internet.

But there is a desire in the Internet industry to bring this standard to 2.0 and bring some major improvements to this standard to cater for today’s Internet reality.

Data multiplexing between client and server

One key capability is to implement the SPDY protocol which supports multiplexing of data between the Web server and the Web browser. This is to provide for faster and efficient data throughput by shifting the data using one “channel”; as well as providing support for managing quality-of-service.

This may involve the deployment of audio and video material under a high quality-of-service while text data and software downloads can pass through on an “as-needed” basis.

Inherent end-to-end encryption support

The SPDY protocol that is to underpin HTTP 2.0 also provides support for end-to-end transport-layer encryption. But Microsoft wanted this feature to be optional so it is implemented according to the needs, such as a blog not needing encryption whereas an Internet banking or device management Web page would need this level of encryption.

But I would also like to support in this feature the ability not just to encrypt data but to authenticate the same data using a digital signature. Here, it could permit users to be sure that the Web site they are visiting or the file they are downloading is authentic and would be especially of importance with field-updated BIOS and firmware deployments, as I raised in my commentary about a lawsuit involving HP concerning this practice and its security ramifications.

Caching support at network level

Another feature that is being proposed is to provide for network-level caching of HTTP data. This is intended to provide for environments like mobile networks where it could be desirable to cache data in the service network rather than on the user’s mobile device; rather than introducing proxy servers to provide this kind of caching.

It will also allow mobile and embedded devices to avoid the requirement to have Web caches for quick loading of Web pages. Of course this will not be needed for those Web pages that have regularly-updated data such as Web dashboards, Web mail or similar applications.

Other issues

It also is worth investigating whether the HTTP 2.0 standard could support applications like client-server email delivery or advanced document authoring such as version control.

Of course this development will take a long time to achieve and will require some form of HTTP 1.x backward compatibility so there isn’t the loss of continuity through an upgrade cycle.

News article

NETGEAR Adds Gigabit PoE Smart Switch – SmallNetBuilder

From the horse’s mouth

NETGEAR GS110TP Gigabit PoE switch product page

NETGEAR GS-110TP Gigabit PoE 8 Port Smart Switch

My comments

The concept of VLANs and quality-of-service functionality is now become increasingly relevant to the home and small-business network now that the “single-pipe triple-play” and “next-generation” broadband Internet services are either here in your market or are coming around the corner to your market.

What are VLANs

The VLAN is a separate logical network path within a physical network medium, such as multiple SSIDs from one Wi-Fi access point serving different networks or a HomePlug setup with multiple Network Passwords for different networks. Most business-grade Ethernet switches offer this functionality in order to have particular Ethernet sockets associated with particular logical networks. It is used in many network applications such as interlinking a business with multiple premises through one multi-tenant building or providing Internet-only “guest access” service to business networks.

Now the VLAN is becoming common in small networks as part of either providing “guest access” or “hotspot service” to the Internet without encroaching on the security of the resident network; or providing dedicated “fast-lanes” for quality of service when it comes to A/V streaming or VoIP service.

NETGEAR’s role in this equation

Now NETGEAR have provided the GS110TP Gigabit Power-Over-Ethernet Smart Switch which is an 8-port switch which offers this functionality and Power-Over-Ethernet to all the ports for US$260. This is similar to how this company offered 5-port and 8-port 10/100Mbps Cat5 Ethernet hubs and switches at prices affordable for most people when the idea of home networking and broadband Internet came on the horizon in the early 2000s. Then a few years later, they offered 8-port 10/100Mbps switches with that had 802.3af standards-based Power-Over-Ethernet supply functionality on four of the ports, again at a price that most users can afford.

It may be easy to think of this unit being a candidate “central” switch when you wire your premises for Ethernet and want to make it future-proof for these new requirements. There have been some concessions to allow it to work properly with “triple-play” by the use of a default VLAN matrix with one VLAN for regular traffic, one for VoIP and one for video traffic. There is some “automatic-transmission” logic that shifts data to the different VLANs based on whether the data was primarily multicast in the case of video or one of a few VoIP protocols in the case of VoIP.

The main problem with this is that this switch wouldn’t work in a “plug-and-play” manner with “edge” devices that use certain VLAN setups or QoS methods to assure video and VoIP quality-of-service. For example, most of the “n-boxes” (Livebox, Neufbox, Freebox, Bbox, etc) used by French “triple-play” service providers as network-Internet edges have one Ethernet port for video traffic and three Ethernet ports for regular traffic. These units would expect you to connect the IPTV box to the “video” Ethernet port and you may end up with QoS or installation difficulties if you used this switch with them.

Limitations with this class of switch

For these switches to become easier to implement in a home or small-business network, there would have to be standards that allow an “edge” device to communicate its QoS and VLAN needs to these switches. This may be important if the “edge” device is managed by the service provider or is part of the provisioning chain that a service provider uses.

This may also include the flexible installation and “at-will” relocation of devices like VoIP handsets or IPTV devices as well as the support for multiple devices of this type across an Ethernet backbone. It also includes the support of multiple cascaded switches such as “regional” switches in other parts of the building or other buildings.

Other benefits to take note of

One bonus that I like about this switch is that it has offered 802.3af-compliant Power-Over-Ethernet across all Ethernet ports which allows the Ethernet cable to be a power cable as well as a data cable.This technology, which I will cover in a separate article on this site, has been pitched at business networks as being suitable for powering Wi-Fi access points, VoIP telephone handsets and IP-based surveillance cameras with one cable and from one point. Infact, NETGEAR have released an 8-port “regional” smart switch that has similar QoS and VLAN functionality but can be powered from this switch or other standards-based Power-Over-Ethernet networks.

Another feature that also appealed to me about this switch is that a unit of this price was equipped with optical-fibre LAN connectivity which can reduce the cost of using optical-fibre as a high-reliability long-distance link between buildings, especially on large properties. 

Conclusion

This is another example of NETGEAR offering technology that is deemed “large business” at prices that home users and small business can afford.

 Will home networks bank on Ethernet?

One of the next points of research that will be appearing for the home network is “Ethernet AV” or “AV-optimised networking”. The main goal with this research is to deliver time-sensitive content like music or video over an Ethernet-based network so it appears at each endpoint at the same time with the bare minimum of jitter or latency.

This research is being pitched at any application where a data network may be used to transport AV information. In the home, this could include multi-room installations where the same programme may be available in different rooms or multi-channel setups where a Cat5 Ethernet, Wi-Fi or HomePlug network link may be used to distribute sound to the rear-channel speakers. In a vehicle or boat, the Cat5 Ethernet cable could be used as an alternative to analogue preamp-level or speaker-level cable runs to distribute audio signals to the back of the vehicle or through the craft. The same method of moving AV signals can appeal to live-audio setups as the digital equivalent of the “snake” – a large multi-core cable used to run audio signals between the stage and the mixing desk that is located at the back of the audience. It can also appeal to the use of IP networks as the backbone for broadcast applications, whether to deliver the signal to an endpoint installed in a home network like an Internet radio or IPTV set-top box; or to work as a backbone between the broadcast studios and multiple outputs like terrestrial radio/TV transmitters and/or cable/satellite services.

The main object of the research is to establish a “master clock” for each logical AV broadcast streams within the home network that represents a piece of programme material. This then allows the endpoints (displays, speakers) to receive the same signal packets at the same time no matter how many bridges or switches the packets travel between the source and themselves.

Once this goal is achieved at the Ethernet level of the OSI stack, it could permit one to implement software in a router to provide Internet broadcast synchronisation for endpoints in a logical network pointing to the same stream. This means that if, in the case of Internet radio, there are two or more Internet-radio devices pointing to one Internet broadcast stream, they appear to receive the stream in sync even if one of the devices is on the wireless segment and another is on the Cat5 Ethernet segment.

This issue will need to be resolved in conjunction with the quality-of-service issue so that time-sensitive VoIP and audio/video applications can have priority over “best-effort” bulk data applications like e-mail and file transfer. Similarly, the UPnP AV / DLNA standards need to implement a quality-of-service differentiation mechanism for bulk transfer compared to media playback because there is the idea of implementing these standards to permit media-file transfer applications like multi-location media-library synchronisation and portable-device-to-master-library media transfer. Here, bulk transfer can simply be based on simple “best-effort” file practices while the time-critical media synchronisation can take place using higher QoS setups.

The other issue that may need to be resolved over the years is the issue of assuring quality-of-service and AV synchronisation over “last-mile” networks like DOCSIS cable, ADSL and FTTH so that IP broadcasting can be in a similar manner to classic RF-based broadcasting technologies. This also includes using the cost-effective “last-mile” technologies for studio-transmitter backbone applications, especially if the idea is to serve “infill” transmitters that cover dead spots in a broadcaster’s coverage area or to feed small cable-TV networks.

Once these issues are sorted out, then the reality of using an IP network for transmitting media files can be achieved.