SIP in higher education

[Garret Yoshimi <>]

Notes from VoIP SIG+SIP.edu Conference Call February 8th, 2007
(Thanks once again to Jeff Kuure for compiling these notes!)

*Attendees*

Steve Blair, University of Pennsylvania
Chris Casswell, MCNC
Candace Holman, Harvard 
Deke Kassabian, University of Pennsylvania
Sean Kent, Level 3
Walt Magnussen, Texas A&M
Joe Milander, University of Oregon
Chris Norton, Texas A&M
Carey Tengler, Level 3
Jonathon Tyman, Internet2
Mike Van Norman, UCLA
Garret Yoshimi, University of Hawaii


*Discussion*

Today's call features Steve Blair and Deke Kassabian from the University of 
Pennsylvania discussing their recent work with Level 3 communications.

Sean Kent, part of a Product Technical Specialist team for Level 3, is on the call to provide an overview of Level 3's services. Carey Tengler, manager of Level 3's Technology Partner Program, is also present. Sean says that Level 3's products are currently targeted at wholesale voice communication companies, but they are looking to work with educational and research organizations as well. In terms of products, they offer voice termination for long distance, local inbound service for DID termination to SIP endpoints, toll free service for PSTN traffic to SIP endpoints, and their enhanced local services, which is a combination of LI and VT products bundled with information services, directory listings, 911, and operator services. 

For getting onto the Level 3 network, they provide a Web interface for 
interoperability testing which gathers end user information through a 
certified soft switch. Level 3 is not a SIP registrar, so rather than 
registering SIP endpoints they would communicate with IP devices such as a 
SER or Broadsoft server. The Web application enables end users to perform 
interoperability testing at their own pace. There are sets of tests for both 
inbound and outbound traffic, with reports generated for approximately 20 
possible call flow scenarios. Some customers have completed the tests over a 
couple of days, with others taking several months. Typically the tests are 
completed in four to six weeks. Sean estimates that for a new client it would 
take one to two months to run the tests, sign any contracts, and begin 
passing live traffic with Level 3.

Following this, Carey talks about Level 3's Technology Alliance Program which 
deals with interoperability issues with different vendors. The bulk of the 
vendors mentioned on Level 3's website are focused on hosting, but a number 
are migrating to a SIP trunking scenario. Broadsoft is one participant, as 
are other PBX vendors like Linksys, Cisco, Avaya, 3COM, Nortel, and Digium. 
Level 3 is still working out the formalities of the interoperability process 
as well as trying to become more proactive in anticipating customer's 
demands. The TAP program does support all of the business divisions within 
Level 3, and covers everything from OSS and BSS applications for back office 
and provisioning to enterprise solutions for voice and data.

Deke and Steve begin to discuss their experience with Level 3 at the 
University of Pennsylvania. Deke mentions that they have a large VoIP project 
at Penn which they refer to as a pilot despite having 800 production users. 
They are using SER as a SIP proxy, Asterisk for voicemail, and the local IP 
infrastructure for transport on campus. Until recently they had (traditional 
PSTN) gateways for the local exchange carriers but recently have switched to 
Level 3 for selected communities of test users, sending traffic completely 
over IP to Level 3's network. There is a lot going on at Penn with VoIP 
beyond the trunking being discussed today, and they would be happy to answer 
any questions in the future.

Steve provides an overview of Penn's current implementation. They are located 
in a dense urban area in Philadelphia, and have a dense wave division 
multiplexing connection to a carrier hotel where they physically peer with 
Level 3. The campus is spread out over a broad geographic area, so they added 
a stand-alone edge proxy to facilitate the distribution of hardware. They 
follow an end-to-end model for the media stream, which passes directly from 
phones to the Level 3 session border controller. Penn has completed the 
outbound peering testing using the commodity internet, and are testing the 
inbound now. Steve says that overall they have had a very positive experience.

At several locations around campus, Penn operates network aggregation points, 
which are environmentally controlled rooms with high-redundancy campus 
backbone connections housing SER and Asterisk servers. The edge proxy 
mentioned earlier is a Dell Poweredge server running RedHat Enterprise 4 and 
OpenSER. This is their only OpenSER server, and was set up because at the 
time SER did not support least cost routing for outbound calling while 
OpenSER did. Steve says that they aren't necessarily going to continue to use 
OpenSER or SER, but notes that they interoperate with no problems. The edge 
proxy serves to provide a level of obscurity to hide their internal 
addressing as well as a place to do LCR and route selection, address writing, 
and other operations required by carriers. For example, peering with Level 3 
requires address to be in the E.164 format. LCR is performed based on NPA NXX 
area codes and exchanges. The North American Numbering Plan's website 
provides a zip file that they reformatted and used to populate their LCR 
table.

For the Level 3 interoperability test, Penn performed the self-paced test 
with the Web application. The portal allowed they to keep an itemized list of 
things that needed to b addressed, which Steve found very useful. He notes 
that they did not have any way of communicating with Level 3 during tests, 
but Level 3 assigned an engineer to work with them over email which helped to 
solve any problems, which he would recommend for others looking for support. 
They completed the test over two months, with Penn's holiday break falling 
during this time for an actual time of about 6 weeks.

They just began inbound testing, and have ported five numbers from Verizon to 
Level 3 and are working on a configuration file for OpenSER. Steve notes that 
they now own these numbers, and will have to handle situations such as DIDs 
being unassigned. They are configuring their edge proxy to play a prerecorded 
message or otherwise deal with these situations, which will hopefully allow
them to manage their number space more effectively and control moves, adds, 
or changes on campus.

Penn has also developed an in-house provisioning tool for VoIP named PIPS. 
They have to integrate ITSP into PIPS, such as the ability for DID assignment 
and unassignment. They also need to have a way to determine if and what type 
of calls can traverse the ITSP connections and which should use the local 
gateway, and have to do this in a way that allows support staff to make 
changes as well
as understand the impact of any changes on end users. They have added the ability to determine on a per-user basis if they can or cannot use the ITSP connection, in anticipation of possible HIPAA and CALEA compliance. Right now Penn is sending traffic from ten to fifteen end users through the connection to Level 3, and some previous echo and static issues have been eliminated and feedback has been positive. 

Walt asks about testing, and if quality was examined or if testing was based 
on completion only. Steve says that only completion was tested for various 
scenarios, such as a call where the RPID says the call should be screened or 
caller ID should be anonymous or where a digit-collection service like PIN 
entry was in place. Call quality has only recently been tested due to some 
issues with the local gateway. Traffic through Level 3 has been an 
improvement.

Walt also asks about secure traffic. Steve says that they are interested in 
this, but have yet to apply any secure protocols to Level 3 traffic. Deke 
says that they would like to use SRTP, but there is a lot of confusion 
regarding HIPAA. He believes that voice calls which are not stored and 
forwarded are not covered by HIPAA, but it might apply for access to 
voicemail.

Candace asks about billing for the project. Steve says that billing is 
addressed in the Level 3 contract, but he isn't the person to talk to about 
this, but he could forward any questions to the finance department. Walt asks 
about customer billing, and if Penn is doing pass-through billing. He also 
wonders how they are dealing with billing for end-to-end IP calls with no 
carrier. Deke says that they don't actually have any case for this right now, 
as users cannot actually conduct end-to-end IP calls right now. When this 
actually happens, they will deal with it. Right now they are preserving the 
standard process of billing for calls and passing charges to end users. Steve
says they currently collect call detail records from the local Cisco gateways which contain well-defined start and stop records for every call. They have sent all-IP calls end-to-end but have yet to figure out how these fit into their business model. 

Deke mentions that although they have 800 users, these users are not making 
off-campus end-to-end IP calls right now. Currently the VoIP project is seen 
as a Centrex replacement project for users, who are looking for Centrex-like 
functionality for calling others with traditional phone sets; they are not 
interested in IP-to-IP dialing or soft clients. Other functionality will be 
introduced in the future, and it will be seen how this affects user's 
day-to-day business tasks.

Garret asks if the monthly charges to IP users is the same as for Centrex users. Steve says that at first the VoIP pricing is less than Centrex charges but will be closer to Centrex pricing after six months. Deke says their goal is to keep the rate at or below the Centrex price, and to possibly drive it down over time. 

Walt asks about inbound 800 calling. Steve says that they have not looked at 
this yet, as no one has asked about it yet.

Candace asks about call trace back through the Level 3 connection. Steve says 
that they are not doing this through Level 3 or through their local gateways, 
but others have asked about this. With SER's accounting module it's easy to 
keep track of calls, but users are used to pressing key sequence to enable 
this and they have not been able to figure out a working solution for this. 
Walt
asks if this is a local switch function, as signaling and caller ID 
information is transmitted with the incoming number. Steve feels that they 
probably could do this but haven't implemented it yet as they've had no 
urgent need.

Following the questions from participants, Steve mentions that from a testing 
point of view everything is going well and he's happy to answer any other 
questions in the future. Walt mentions that Texas A&M is looking to move at 
least half of their traffic to IP trunks and getting rid of half a dozen PRIs.