Network and Telecom Strategies Blog

New Developments in Telepresence

posted by: Mark Cortner

The telepresence market appears to be maintaining its market momentum and acceptance given numerous vendor and carrier announcements over the last several weeks. The most visible infrastructure vendor in these announcements has been Cisco, a strong proponent of visual collaboration technologies. Cisco has been a driving force in the telepresence market and the combined positioning of telepresence to its enterprise and service provider customers is generated several interesting announcements.

Cisco recently announced that it had successfully demonstrated the industry’s first telepresence session across multiple carrier networks. The demonstration occurred coincident with Cisco Live 2009 and consisted of inter-carrier telepresence connections between seven sites on the AT&T, BT, and Tata Communications networks.  The demonstration verified the technical ability for a business using Cisco’s telepresence solution to utilize telepresence services to collaborate with any other business or location that is also utilizing Cisco’s telepresence solution.

The ability to initiate and reliably conduct a telepresence session across multiple carrier networks will resonate with large global enterprises, as they frequently utilize multiple carriers to provide network connectivity to their worldwide facilities. Furthermore, the ability to conduct an inter-carrier telepresence sessions enables business-to-business or inter-enterprise telepresence usage—effectively expanding the number of addressable telepresence suites for an enterprise and driving more utility out of investments in visual collaboration infrastructure and services. The demonstration by Cisco, AT&T, BT, and Tata Communications is a great first step; ultimately the telepresence infrastructure vendors and carriers need to demonstrate telepresence over multiple networks with connections different third-party telepresence systems – that’s interoperability.

QoS Problems With VoIP Over Wireless

Posted by: Eric Siegel

A fascinating article, "Coexistence of VoIP and TCP in Wireless Multihop Networks," was just published in the June 2009 edition of IEEE Communications Magazine (vol 47, issue 6, pp 75-81; the authors are Kyungtae Kim and Dragos Niculescu [NEC Laboratories America] and Sangjin Hong [Stony Brook University - SUNY]).

Burton Group has been warning that using VoIP over wireless LAN (VoWLAN) is tricky because "QoS alone cannot completely regulate the bandwidth provided to flows on a wireless network... a single wireless station on a shared wireless channel can degrade performance for all other stations on the channel...." We've been saying that: "A reasonable alternative is to avoid voice over WLAN altogether, substituting cellular voice, possibly with femtocell or in-building repeater technology." (See the Burton Group reports "Quality of Service (QoS) Alternatives" and "Demystifying Radio Management" along with the Technical Position "Quality of Service".)

This new article shows that the problems created by VoIP over wireless LAN are even worse than I'd thought. The authors did some experiments, and they found that TCP and VoIP do not coexist well on a wireless LAN. TCP's large frame sizes, large receive windows (RWIN), bursty traffic, and retransmission when a frame is lost make it interfere with short, evenly-spaced VoIP frames. The TCP frames will dominate radio transmissions because of the frame lengths and frequency during a burst. (Frames can't be interrupted after they start to transmit; therefore, long, frequent TCP frames will dominate over infrequent, short VoIP frames.)

Worse, the self-interference and half-duplex characteristics of a wireless LAN system increase the probability that the long TCP data bursts will need retransmission, further increasing their burstiness and their domination of the channel when compared to short VoIP frames. (Self-interference occurs when a single flow interferes with itself as it travels over the wireless system. When transmission and reception share the same half-duplex radio channel, a stream may compete with its own acknowledgements for radio time, delaying or destroying some data and acknowledgement packets. If transmission hops over a couple of radio links in sequence, then each hop's transmission may interfere with transmissions on other hops that are within reception range; a flow may interfere with itself.)

The authors of the new article show that no standard type of queuing algorithm in routers adjacent to the wireless network, even Priority Queuing (PQ), can handle these problems. And they also show that five standard TCP variants used in end stations (TCP Reno, TCP Vegas, TCP Westwood, TCP CUBIC [used in Linux], and C-TCP [used in Windows Vista and Server 2008]) do not handle these problems. In all cases, the TCP flows dominate and degrade the VoIP flows.

What should be done? Well, Burton Group has recommended that cellular should be considered instead of VoWLAN. The authors of the study make additional suggestions that sound interesting, but they also warn that none of them is a panacea - they all are only partial solutions, at best. The authors warn that "the methods examined here have straight-forward application only when the wireless capacity is fixed. In reality, the capacity is highly variable." They also warn that P2P, uploading traffic, and interactive streaming, such as Skype, that use TCP for voice will complicate the situation even more.

The paper's most interesting recommendations are:

• Use unusually-small TCP receive windows and eliminate TCP bursts on the wireless LAN. This may need to be done by gateways at the wired:wireless interface. The gateway would use smaller TCP packets and a small receive window; it would also use a buffer to ensure that any bursts were smoothed out and that TCP packets were spaced out to reduce self-interference and interference with VoIP frames. 

• Use a traffic shaping system. The article says, "After a packet of size pkt_size goes out over the air, the next packet is scheduled no earlier than pkt_size/R. The gateway chooses R based on the network status to determine how much to send as well as when to send."

Other papers have recommended different methods, such as doing priority queuing at all intermediate wireless nodes and combining that with traffic shaping.

At this time, it seems to me that avoiding sharing the same channel between TCP and voice is still the best solution.

Closing in on Catalyst

Posted by: Michael Disabato

The preparation for Catalyst includes reviewing all the presentations that will be given. While this is a lot of work (NTS reviews 18 presentations in our track and about 20 more in other tracks), We get an excellent sense of where the conference will be headed. We have consistently improved Catalyst through one simple tactic: We listen to our attendees. We hear you when you talk about the things that keep you up at night. We look through the corridor of time to the future and see what will be exciting to you when it's ready for prime time. We present that in a forum where you can meet and greet your peers and the presenters.

If you have not made plans to attend Catalyst 2009, head over to the Burton Group web site, take a look at the agenda, and make your reservations today. We are indeed covering the right issues with the right speakers, and this is the right time to hear what they have to say.

Michael

I hate when I'm right. Sometimes.

Posted by: Michael Disabato

As I blogged before, the Sprint/Pre combination is not the iPhone killer that was predicted:

 June 17 (Bloomberg) -- Sprint Nextel Corp. and Palm Inc. shares fell after an analyst at Wachovia Securities Inc. signaled the new Pre touch-screen phone may not be luring customers away from rival carriers. A survey of retail sites showed that most buyers of the Pre are already Sprint subscribers, helping the carrier retain customers.


What does this mean? Little or no growth for Sprint. Faint hope of recovery for Palm. Their CEO departed on June 11 after "sixteen years of leadership". Some leadership. The cadre of developers has dispersed to more profitable platforms. Their mindshare has all but evaporated. Their last offering (Windows Mobile) was so stunning (not), no mobile operator would subsidize it.

Had the Pre been on a GSM network (T-Mobile?) it might have had a chance. Instead, it's on a CDMA network on frequencies used in the United States. And that network is the smallest of the "Big Four." Palm lacks a compelling story. Sprint has made some dubious technology choices. The result is evident.

What where they thinking indeed.

Michael

Tax Relief - Maybe

Posted by: Michael Disabato

A few days ago I posted about an effort by the IRS to revive and revise a lay that is basically ignored by employees and employers alike that would have taxed personal use of business cell phones. Now, the Wall Street Journal, among others, have reported that the IRS is backing off.

"IRS Commissioner Doug Shulman on Tuesday asked Congress to repeal the 20-year-old law to ensure that neither companies nor workers will be subject to taxes for employees' personal use of work cellphones. The request is a turnabout from last week, when the IRS proposed measures to improve enforcement of the law, which is now widely ignored by employers and employees."

Evidently, more rational thought is prevailing. Either that, or someone is reading the blogs and tweets about this that universally said the IRS is out of touch (no surprise there).

Keep at it, folks. Mail bomb your congress critters and tell them what a stupid idea this is given the current technical and economic environment of the mobile industry. Then go ask them to work on handset exclusivity and subsidies. ;)

Michael

ITIL Version 3 Overview

Poste by: Michael Disabato

Last week I spoke at a BrightTalk summit on ITIL and gave an overview of Version 3. If you are interested, the talk is repeated here.

Enjoy!

Michael

Taxing Mobile Phones

Posted by: Michael Disabato

The IRS is at it again. According to the Washington Post and the Wall Street Journal, the IRS is working on "simplifying" a 20-year old rule that requires the value of employer-issued cellphones to be included in workers' gross income, unless an employee kept detailed records showing the phone was used only for work. The law was passed in the late 80's (last century) when mobiles were a comparative rarity. Since more business calls are now made on mobiles than landlines, and there are more mobiles than wired phone accounts in the U.S. (something that has existed in Europe for a long time), the law would seem to be antiquated.

According to the Journal:

"The Internal Revenue Service proposed employers assign 25% of an employee's annual phone expenses as a taxable benefit. Under that scenario, a worker in the 28% tax bracket, whose wireless device costs the company $1,500 a year, could see $105 in additional federal income tax."

This is going to cause a real mess for employers and employees alike. I strongly urge you to contact your Congress-critter, vent your displeasure, start blogging and tweeting about it, and generally raise a royal stink.

Michael

Evaluating Change Management

Posted by: Michael Disabato

The Change Management process is one of the most important processes that will be developed. Change Management ensures the stability and security of the infrastructure. Unauthorized or rushed changes account for a significant source of service interruptions and can open a company to potential security breaches.

The best way to determine the quality of the Change Management process is to examine five indicators:

• The number of unauthorized changes
• The number of unplanned outages
• The change success rate
• The number of emergency changes
• The number of delayed project implementations

Any number of unauthorized changes above zero indicates your process has failed. Find out who is bypassing the process and discipline them.

If the unplanned outages can be traced back to the changes being made (and some, if not most of them will), the process needs rework in the risk management and QA phases.

A high change success rate means you can cautiously celebrate. A low change success rate means you need to post-mortem each change and see where they went awry.

Emergency changes generally are caused by incorrectly applied changes. This indicates the testing process is flawed and needs to be reexamined.

Delaying projects is never a good thing. If delays can be tracked back to the change process, find out what the cause is and fix it.

Change management is not hard, but it is critical to the success of the IT department.

Michael

The Future of UC and the Cloud: Google Wave?

posted by: Mark Cortner

The future of real-time communications and the cloud took an interesting twist recently when Google showcased a new communication and collaboration tool: Google Wave.  Google Wave is a browser-based application that creates a shared online desktop where multiple users can interact and collaborate. As described by its inventors, Google Wave is what email would look like if it were invented today.

The base applications embedded within Wave include email and instant messaging; though essentially these applications are now unified together and become a conversation in the cloud as opposed to messages sent from one place to another.  The conversation or “wave” becomes a shared communication space with email, instant messaging, and social networking elements.  Furthermore, a wave may consist of a full, integrated collaborative experience that includes rich document editing and sharing and the ability to save and store any “Wave” resulting from their interaction to the Web.

Interestingly, the questions that the inventors of Google Wave started with are very similar to those connected with the topic of unified communications (UC):

• “Why do we have to live with divides between different types of communication –  email versus chat, or conversations versus documents?”
• “Could a single communications model span all or most of the systems in use on the web today in one single continuum?”
• “What if we tried designed a communications system that took advantage of computers current abilities, rather than imitating non-electronic forms?”

The parallels to UC are very close; the concepts of breaking down silos of communication to an integrated or unified experience, transitioning from single-purpose infrastructure to multi-application infrastructure, and adapting user experience to advanced in computing and networking technologies. Google Wave diminishes the role of the computer desktop in the future of computing … and could impact the future role of unified desktop clients and cloud-based services for UC!  

iPhone 3Gs and Release 3.0 - my thoughts

posted by: Paul DeBeasi

Apple announced the iPhone 3Gs and release 3.0 today. The iPhone 3Gs will be available in about a week.The 16 GB version is $199, the 32 GB version is $299. The older iPhone 3G price drops to $99. (Note the pricing caveat at the bottom!)Release 3.0 is a free upgrade. Here is my take:

What I like :-)

Hardware encryption – Finally! An enterprise can perform iPhone encryption. Expect to see 3^rd party security applications take advantage of this capability in the near future.

Instantaneous remote-wipe – An essential capability for any enterprise. Expect to see 3^rd party management applications like Trust Digital and Credant to support this capability in the near future.

Supports HSPA+ (7.2Mpbs download) – Nice, but the REAL question is WHEN will AT&T improve overall wireless performance (Radio Access Network AND backhaul network) so that the end user experiences a significant performance boost?

iPhone tethering – This allows a laptop or PC to use the 3G network for communication. Unfortunately, AT&T is not supporting this feature!

Apps load/run 2- 3 times faster – Who doesn’t love this?

Improved battery life – WiFi-9 hrs, audio-30 hrs, video-10hrs – This is good, but 3G talk time did not improve (still 5 hours) and 2G talk time improved a little (5 to 7 hours).

Voice activated commands (includes voice activated dialing) – This is a “me too” feature that Apple has integrated into other apps (not just voice dialing).

Video camera and embedded compass – These are nice, but not really necessary for the enterprise.

Remote control of 3^rd party hardware – Release 3.0 now allows software developers to create wireless protocols that operate between the iPhone and 3rd party hardware.  At the WWDC today, Apple showed an iPhone communicating with Johnson and Johnson a heart monitor.  This capability allows enterprises to develop custom applications that integrate the iPhone with their products.

Cut and paste – Finally!

MMS – Finally! (But, AT&T will not have this capability until Fall 2009). 

What I don’t like :-(

Poor iPhone provisioning – The iPhone does not yet support real “over the air” provisioning.  If an IT department wants to provision an iPhone (3G or 3Gs), they need to email the configuration profile to the user and then the user installs the profile. Alternatively, an IT department can email /text a URL to each user and then the user needs to click on the URL to initiate profile installation.  This is kind of kludgy because it requires end user intervention. I prefer this capability to be under IT control.

No SDRAM slot – Can’t add more memory ingdings

No user-facing video camera – No video conferencing yet!

Expensive upgrade– For existing AT&T customers who want to replace an iPhone 3G, the price with a new two-year agreement is $599 (16GB), or $699 (32GB)!

All in all, this is a good step forward and will put further pressure on IT departments to support the iPhone.