<ul><li>GPON: The Standard for PON Deployment and Service Evolution </li></ul>Ron Hartkemeyer Director Support Services Op...
<ul><li>Industry Leader </li></ul><ul><ul><li>More Than 203 Fiber Powered  </li></ul></ul><ul><ul><li>Communities </li></u...
US Optical Fiber Communities     FTTH Council Publication May 10 th  , 2005 OSI Deployed in 51% or 203 of 398 communities
US Optical Fiber Communities excluding RBOC deployments     FTTH Council Publication May 10 th  , 2005 Excluding RBOC depl...
Standards Based PON Protocols <ul><li>Standards Bodies That Have Specified PON Protocols </li></ul><ul><ul><li>Internation...
Major Members Of Full  Service Access Network (FSAN) FSAN Recommends Standards to the International Telecommunications Uni...
FiberPath GPON Network GPON = 25 dB/20km/12.4 Miles Optical Line Terminals (ONT’s)
Drivers for GPON <ul><li>Correction of BPON  Limitations </li></ul><ul><ul><li>Higher Speeds </li></ul></ul><ul><ul><li>Sc...
GPON Status and Time Line <ul><li>G.984.1 – Service Requirements  </li></ul><ul><ul><li>Transport speeds and feeds, tolera...
GPON Additions in Work <ul><li>IPTV over GPON </li></ul><ul><ul><li>First Specification for standardizing IPTV service del...
FSAN PON bit rates G.983 BPON framing G.984 GPON framing   2.4 Gbps 2.4 Gbps 1.2 Gbps 1.2 Gbps 622 Mbps 622 Mbps 155 Mbps ...
ITU-T G.984.2 Physical Media Dependent Layer <ul><li>8.2.1 Digital Signal Nominal Bit Rate </li></ul><ul><ul><li>Transmiss...
<ul><li>ITU-T G.652 Single Mode Fibre  </li></ul>8.2.2.1  Transmission Medium: <ul><li>Upstream Wavelength Range = 1260 – ...
ITU-T G.984.3 Transmission Convergence Layer <ul><li>5.3 Multiplexing Architecture </li></ul><ul><ul><li>Two Multiplexing ...
Forward Looking GPON Standards   BPON GPON or 155 622 1.2 2.4 <ul><li>GPON Rated to 2.4 Gigabit Symmetrical </li></ul><ul>...
GPON Voice Migration of Telephony Networks <ul><li>TDM/GR-303 Voice Network </li></ul><ul><ul><li>DS1’s used for GR-303 In...
Standards Speeds and Feeds Protocol designed for IP traffic.  GPON took the best of EPON and BPON in the development of th...
Standards Comparison Less than 75% Greater than 90% Bandwidth efficiency 1.25 Gb/s 2.4 Gb/s Maximum PON Speeds Left to ven...
<ul><li>Shorter Link Budgets </li></ul><ul><ul><li>Limited Design Options </li></ul></ul><ul><ul><li>More Actives In OSP <...
Standards Comparison Line Coding OH PON burst OH
G.983 (BPON) vs G.984 (GPON) <ul><li>BPON supports only ATM cells </li></ul><ul><li>GPON supports both ATM and GEM  </li><...
PON Standards - Summary <ul><li>GPON (G.984) improvements over BPON (G.983) </li></ul><ul><ul><li>Efficiency: dual mode su...
<ul><li>PON Protocol Standards Matter </li></ul><ul><ul><li>Reliability & Availability </li></ul></ul><ul><ul><li>Mass Ado...
Upcoming SlideShare
Loading in …5
×

OSI confidential information GPON: The Standard for PON ...

6,526 views

Published on

Published in: Business, Technology
1 Comment
2 Likes
Statistics
Notes
No Downloads
Views
Total views
6,526
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
769
Comments
1
Likes
2
Embeds 0
No embeds

No notes for slide
  • This slide introduces the two standards bodies for the development of PON protocols. One is the ITU, which is the international organization that typically develops standards for the telecommunications industry. This is the body that has developed standards for HDSL, ADSL, SS7, etc. All of the large carriers in the world belong and support the ITU. IEEE is another standards group focused on the engineering community and has increasingly taken on a standards role in the last 5-10 years, primarily in the enterprise IT marketplace. But as data and telephony continue to converge, they are involved in some of the telecommunications standards work. Standards are important because they drive the underlying protocols and the basic specifications for specific telecom and data systems. These protocols and specifications are the heart the various PON’s variants. Ultimately, these protocols define the specific to make interoperability a reality and to insure that the products will perform. Three standards have been ratified; BPON and GPON by the ITU-T and EPON by the IEEE. Any other protocol is not a standard- PERIOD. Any of our customer should understand that any other solution is Proprietary and as we all know, it makes no sense to make a long term investment in proprietary systems in today’s world.
  • FSAN is the body that is responsible in making recommendations to the ITU concerning PON standards. This is a partial list of the carriers that participate and are active in working with a host of vendors around the standard. Dr. David Cleary is the OSI representative on the FSAN body and has been for the last 4+ years. He has been intimately involved with developing the standard to insure that the final product will meet the needs of service providers both today and in the future. This is an international standard as represented by the list of world-wide service providers participating in FSAN.
  • The advantages of GPON are key in driving the commitment by the large volume carriers to the GPON standard. GPON is the standard of choice for FTTP, which will continue the accelerated cost reductions and inter-operability. GPON has higher speeds today and at path to still higher speeds as the cost of optics and bandwidth requirements reach the right points. GPON not only has lower cost optics today the external interfaces to the core are all Gigabit interfaces GPON is IP centric, yet acknowledges the strengths of the operator being able to differentiate themselves on QOS. GPON continues to have a long reach that effectively eliminates active components in the access network. Driving down engineering time, eliminating expensive site acquisition and powering and the on-going maintenance and operating expenses of active elements in the access network.
  • Here are some of the key underlying specifications that are part of the GPON G.984.2 standard. This is just the physical media dependent layer and it is indicative of the reason why standards are the first step toward inter-operability. Here are some of the highlights from this standard transmission rate is in multiples of 8kHz, which is the existing timing standard for most of today&apos;s transport equipment. The standard provides fro 1244.16Mb/s downstream and 622.08mb/sec upstream. This is not an even number because it must meet the requirements of the 8khz multiple. Later you’ll see how important and why this is. This building on the standard 8kHz timing provide GPON with inherent framing within the transport unlike EPON where the timing has to be added in. Transmission medium- single mode fiber Operating wavelength- downstream window is 1480-1500nm our FiberPath system works at 1490 nm. Upstream wavelength is 1260-1360 nm and FiberPath is 1310 nm. Attenuation Range- Class B lasers with 25 dm of link margin Maximum distance between OLT and ONT- standard provides for 20km or about 12+ miles, but this is dependent on the losses in the fiber access network. The logical distance is significantly longer and OSI is testing optical equipment to extent this distance even farter.
  • Here are some of the key underlying specifications that are part of the GPON G.984.2 standard. This is just the physical media dependent layer and it is indicative of the reason why standards are the first step toward inter-operability. Here are some of the highlights from this standard transmission rate is in multiples of 8kHz, which is the existing timing standard for most of today&apos;s transport equipment. The standard provides fro 1244.16Mb/s downstream and 622.08mb/sec upstream. This is not an even number because it must meet the requirements of the 8khz multiple. Later you’ll see how important and why this is. This building on the standard 8kHz timing provide GPON with inherent framing within the transport unlike EPON where the timing has to be added in. Transmission medium- single mode fiber Operating wavelength- downstream window is 1480-1500nm our FiberPath system works at 1490 nm. Upstream wavelength is 1260-1360 nm and FiberPath is 1310 nm. Attenuation Range- Class B lasers with 25 dm of link margin Maximum distance between OLT and ONT- standard provides for 20km or about 12+ miles, but this is dependent on the losses in the fiber access network. The logical distance is significantly longer and OSI is testing optical equipment to extent this distance even farter.
  • This slide shows the standards effort around the convergence layer of the GPON protocols. The key points are the following- There are two multiplexing mechanisms ATM &amp; GEM (GPON Encapsulation Mode) Frames within the GPON convergence layer can be a mix of ATM and GPON GEM is 10% more efficient than BPON at carrying IP traffic Because GPON does not require 8b/10B Ethernet encoding, which is a requirement to get a QOS capability in EPON, it is 20% more efficient than EPON in carrying IP traffic. With the 125 micro-second framing the timing of information is implicit within the GPON protocols.
  • The point of this slide is the inherent in the GPON standards is the forward-looking capability within the inherent standard for future needs. Customers putting in Fiber know the advantage of fiber as a long-term infra-structure, it naturally makes sense to have that same forward vision in their FTTP system. GPON inherently has that built into the standards, which is why both carriers and suppliers are committing to GPON as the system of choice. This slide shows a comparison of GPON and BPON on speed. GPON is a point-to-multipoint system in the downstream direction and point to point in the up stream direction. This means the OLT transmits to all of the ONT’s on the PON, and the ONT’s only accept the information that is meant for that ONT’s specific customer. But on the upstream where the system transport architecture is point to point each ONT has to be ask permission of the OLT to talk in the up-stream. The system does this by few bytes to the OLT asking for permission to transmit and allowing the OLT to range that particular ONT and set the right levels in the OLT receiver. BPON used a fixed 3 byte burst to gain this permission. Unfortunately, this resulted in an actual limit on the up-stream bandwidth of 155mb/s. With GPON the standard allows the burst request to vary in length so that has the GPON is up-graded to higher speeds this protocol will automatically change to accommodate these higher speeds.
  • The GPON standard also provides a migration path from today’s PSTN network to a fully IP supported infra-structure. We start out with legacy PSTN and separate internet networks. Phase two provides an IP stack upgrade which incorporates a VOIP gateway. Phase three provides full IP support on an additional software upgrade.
  • This slide compares the actual payload (or usable) bandwidth available on BPON, EPON and GPON. This is where we can emphasize that the FSAN standard is well thought out and designed with the needs of both IP traffic and QoS in mind. GPON delivers more usable bandwidth, which for our customers, translates into more revenue capability than EPON or BPON. What is interesting is that even at the same transport speed (EPON and GPON) of 1.2Gb/s, the overhead that has to be added to EPON to make that system work sucks up all of the bandwidth leaving less for actual revenue producing services.
  • OSI confidential information GPON: The Standard for PON ...

    1. 1. <ul><li>GPON: The Standard for PON Deployment and Service Evolution </li></ul>Ron Hartkemeyer Director Support Services Optical Solutions
    2. 2. <ul><li>Industry Leader </li></ul><ul><ul><li>More Than 203 Fiber Powered </li></ul></ul><ul><ul><li>Communities </li></ul></ul><ul><ul><li>More Than 55,000 Optical Network Terminals </li></ul></ul><ul><ul><li> (ONTs) Deployed </li></ul></ul><ul><ul><li>Shipping More Than 4,000 GPON ONTs Per Month </li></ul></ul><ul><ul><li>1 st ITU Compliant GPON Product (Shipping Since 2003) </li></ul></ul><ul><ul><li>1 st IPTV Over PON Deployment in Nation (IPTV Since 2002) </li></ul></ul><ul><ul><ul><li>More Than 90% of the PON IPTV Installs in the World </li></ul></ul></ul><ul><ul><li>Active Member and Editor of FSAN Standards Committee </li></ul></ul><ul><ul><li>One of Three Founders of FTTH Council and Presently on the Board of Directors </li></ul></ul><ul><ul><li>Significant Patent Portfolio in FTTP Technology </li></ul></ul>About Optical Solutions
    3. 3. US Optical Fiber Communities FTTH Council Publication May 10 th , 2005 OSI Deployed in 51% or 203 of 398 communities
    4. 4. US Optical Fiber Communities excluding RBOC deployments FTTH Council Publication May 10 th , 2005 Excluding RBOC deployments OSI Deployed in 61% or 203 of 333 communities
    5. 5. Standards Based PON Protocols <ul><li>Standards Bodies That Have Specified PON Protocols </li></ul><ul><ul><li>International Telecommunication Union (ITU-T) </li></ul></ul><ul><ul><li>Institute of Electrical & Electronics Engineers (IEEE) </li></ul></ul><ul><li>Three Fully Ratified PON Protocol Standards Exist </li></ul><ul><ul><li>ITU-T Ratified BPON (G.983) & GPON (G.984) </li></ul></ul><ul><ul><li>IEEE Ratified EPON (802.3ah) </li></ul></ul><ul><ul><li>Non Compliant PONs are Proprietary </li></ul></ul>
    6. 6. Major Members Of Full Service Access Network (FSAN) FSAN Recommends Standards to the International Telecommunications Union (ITU)
    7. 7. FiberPath GPON Network GPON = 25 dB/20km/12.4 Miles Optical Line Terminals (ONT’s)
    8. 8. Drivers for GPON <ul><li>Correction of BPON Limitations </li></ul><ul><ul><li>Higher Speeds </li></ul></ul><ul><ul><li>Scalable to still higher speeds with the on-going decreases in optics costs </li></ul></ul><ul><li>Recognition of IP Networking </li></ul><ul><ul><li>Evolution From ATM to Pure IP Transport </li></ul></ul><ul><li>Platform for All Services Delivery </li></ul><ul><ul><li>Video - IPTV or RF </li></ul></ul><ul><ul><li>Voice - TDM or VoIP </li></ul></ul><ul><ul><li>Data </li></ul></ul><ul><li>Platform Designed for Interoperability and lower operations costs </li></ul><ul><ul><li>Standards driven interoperability </li></ul></ul><ul><ul><li>No Active Powering Points in the access Network </li></ul></ul>(FSAN committee has been working on GPON since mid 2001)
    9. 9. GPON Status and Time Line <ul><li>G.984.1 – Service Requirements </li></ul><ul><ul><li>Transport speeds and feeds, tolerances and delays, etc </li></ul></ul><ul><ul><li>Ratified by ITU-T in 01/03 </li></ul></ul><ul><li>G.984.2 – PMD – Physical Media Dependent Layer </li></ul><ul><ul><li>Link budgets by class, split ratios, etc </li></ul></ul><ul><ul><ul><li>Class B ODN – 10dB min to 25 dB Max loss </li></ul></ul></ul><ul><ul><li>Ratified by ITU-T on 01/03 </li></ul></ul><ul><li>G.984.3 – TC - Transmission Convergence Layer </li></ul><ul><ul><li>Transport Protocol Layer </li></ul></ul><ul><ul><li>1/04 : ITU-T Approved </li></ul></ul><ul><li>G.984.4 – OMCI – ONT Management and Control Interface </li></ul><ul><ul><li>This specification lays the groundwork for interoperability. </li></ul></ul><ul><ul><li>1/05: ITU-T Approval (expected in Q4 2005) </li></ul></ul>
    10. 10. GPON Additions in Work <ul><li>IPTV over GPON </li></ul><ul><ul><li>First Specification for standardizing IPTV service delivery mechanisms and requirements </li></ul></ul><ul><li>TDM over a GEM only Transport </li></ul><ul><ul><li>Establish QoS for TDM traffic in a GEM only Mode </li></ul></ul>
    11. 11. FSAN PON bit rates G.983 BPON framing G.984 GPON framing 2.4 Gbps 2.4 Gbps 1.2 Gbps 1.2 Gbps 622 Mbps 622 Mbps 155 Mbps 155 Mbps Downstream Upstream 2.4 Gbps 2.4 Gbps 1.2 Gbps 1.2 Gbps 622 Mbps 622 Mbps 155 Mbps 155 Mbps Downstream Upstream
    12. 12. ITU-T G.984.2 Physical Media Dependent Layer <ul><li>8.2.1 Digital Signal Nominal Bit Rate </li></ul><ul><ul><li>Transmission Line Rate = Multiple of 8 kHz </li></ul></ul><ul><ul><li>Nominal Line Rates </li></ul></ul><ul><ul><ul><li>Downstream = 1244.16 Mbit/s </li></ul></ul></ul><ul><ul><ul><li>Upstream = 622.08 Mbit/s </li></ul></ul></ul><ul><li>8.2.2.1 Transmission Medium </li></ul><ul><ul><li>ITU-T G.652 Single Mode Fiber </li></ul></ul><ul><li>8.2.5 Operating Wavelength </li></ul><ul><ul><li>Downstream Wavelength on Single Fiber=1480–1500 nm (FP500 is 1490nm) </li></ul></ul><ul><ul><li>Upstream Wavelength = 1260 – 1360 nm (FP500 is 1310) </li></ul></ul><ul><li>8.2.7.1 Attenuation Range </li></ul><ul><ul><li>CLASS B = 25 dB </li></ul></ul><ul><li>Table 4-a, Item 7 Maximum Fiber Distance Between S/R & R/S Points </li></ul><ul><ul><li>Maximum Fiber Distance Between OLT and ONU – 20km/12.4 miles </li></ul></ul>
    13. 13. <ul><li>ITU-T G.652 Single Mode Fibre </li></ul>8.2.2.1 Transmission Medium: <ul><li>Upstream Wavelength Range = 1260 – 1360 nm (FP-500 = 1310 nm) </li></ul><ul><li>Downstream Wavelength Range on Single Fibre Systems = 1480 – 1500 nm (FP-500 = 1490 nm) </li></ul>8.2.5 Operating Wavelength: <ul><li>CLASS B = 25 dBm </li></ul>8.2.7.1 Attenuation Range: <ul><li>Maximum Fibre Distance Between OLT & ONU = 20 km/ 12.4 mi (60km Logical Reach) </li></ul>Table 4-a – Item #7 Maximum Fibre Distance Between S/R & R/S Points: ITU-T G.984.2 Physical Media Dependent Layer <ul><li>Transmission Line Rate = Multiple of 8 kHz </li></ul><ul><li>Nominal Line Rates Downstream/Upstream = 1244.16 Mbit/s / 622.08 Mbit/s </li></ul>8.2.1 Digital Signal Nominal Bit Rate:
    14. 14. ITU-T G.984.3 Transmission Convergence Layer <ul><li>5.3 Multiplexing Architecture </li></ul><ul><ul><li>Two Multiplexing Mechanisms: ATM and GEM (GPON Encapsulation Mode) </li></ul></ul><ul><ul><li>Frame can be Mix of ATM or GEM </li></ul></ul><ul><ul><li>GEM = 10% More Efficient than BPON in Carrying IP Traffic </li></ul></ul><ul><ul><li>GPON Does not Require 8b/10b Ethernet Encoding Requirement of EPON </li></ul></ul><ul><ul><li>GPON = 20% More Efficient than EPON in Carrying IP Traffic </li></ul></ul><ul><li>8.1 Downstream Frame Structure </li></ul><ul><ul><li>125 Micro-seconds in Length = 8 kHz = Clocking Implicit in Frame </li></ul></ul>
    15. 15. Forward Looking GPON Standards BPON GPON or 155 622 1.2 2.4 <ul><li>GPON Rated to 2.4 Gigabit Symmetrical </li></ul><ul><li>GPON Byte Burst Overhead Increases w/Upstream Speed </li></ul><ul><li>BPON Effectively Limited to 155 Mbps upstream </li></ul><ul><li>BPON Fixed 3 Byte Burst Overhead </li></ul><ul><li>Turn on times less than 50 ns are high cost </li></ul>
    16. 16. GPON Voice Migration of Telephony Networks <ul><li>TDM/GR-303 Voice Network </li></ul><ul><ul><li>DS1’s used for GR-303 Interface @ OLT </li></ul></ul><ul><ul><li>VoIP overlay with IAD (Integrated Access Device) </li></ul></ul><ul><ul><ul><li>IAD is stand-a-lone (inside premises) </li></ul></ul></ul><ul><ul><ul><li>IAD has Ethernet and POTS interface </li></ul></ul></ul><ul><li>TDM/GR-303 with VoIP Voice Network </li></ul><ul><ul><li>DS1’s used for GR-303 interface @ OLT </li></ul></ul><ul><ul><li>Voice Gateway used to convert calls to VoIP </li></ul></ul><ul><ul><li>OLT Ethernet interface used for VoIP </li></ul></ul><ul><ul><li>IAD function is performed by ONT </li></ul></ul><ul><li>VoIP Voice Network </li></ul><ul><ul><li>Ethernet interface at OLT used for all voice services </li></ul></ul>GR-303 DS1’s Ethernet POTS IAD Ethernet IAD POTS Ethernet IAD POTS Ethernet GR-303 DS1’s Ethernet Ethernet Voice Gateway Ethernet
    17. 17. Standards Speeds and Feeds Protocol designed for IP traffic. GPON took the best of EPON and BPON in the development of the standard <ul><li>1.24 or 2.4 Gigabits/sec downstream </li></ul><ul><li>622 Mb/sec up to 2.4 Gigabits/sec upstream </li></ul><ul><li>Optional RF video overlay </li></ul><ul><li>Up to 64 way split </li></ul><ul><li>20 km reach </li></ul>ITU Approved April 2003 GPON Strictly an ATM-based protocol (APON) with an RF overlay for video delivery <ul><li>622 Mb/s downstream </li></ul><ul><li>155 Mb/s upstream </li></ul><ul><li>RF Video overlay </li></ul><ul><li>16 and 32 way split </li></ul><ul><li>20/10 km reach </li></ul>ITU Approved 2001 (APON version approved 1998) BPON Ethernet in first mile implementation <ul><li>1.2 Gigabits/sec downstream </li></ul><ul><li>1.2 Gigabits/sec upstream </li></ul><ul><li>16 way split </li></ul><ul><li>10 km reach </li></ul>IEEE Approved 2004 EPON Dead end system <ul><li>Varies by manufacture </li></ul>None Designed by manufacturer Proprietary Comments Key parameters Official Standards body Status Standard
    18. 18. Standards Comparison Less than 75% Greater than 90% Bandwidth efficiency 1.25 Gb/s 2.4 Gb/s Maximum PON Speeds Left to vendor Specified Security Left to vendor Specified Network synchronization Left to vendor Specified QoS 24 dB 25 dB Attenuation Range Specified Specified Wavelengths One person- One vote Carriers drive and approve vendors technical recommendations Committee Operating Protocol Enterprise and consumer market focused Service Provider focused Attendees Ethernet in the First Mile (EFM) Full Service Access Network (FSAN) Mission/Objective IEEE (P-P & EPON) ITU (GPON)
    19. 19. <ul><li>Shorter Link Budgets </li></ul><ul><ul><li>Limited Design Options </li></ul></ul><ul><ul><li>More Actives In OSP </li></ul></ul><ul><ul><li>Increased Op Ex $ </li></ul></ul><ul><ul><li>Less Reliable </li></ul></ul>GPON Reach Advantage over EFM GPON = 20km EFM = 20km REACH GPON = 40 km REACH EFM = 10km
    20. 20. Standards Comparison Line Coding OH PON burst OH
    21. 21. G.983 (BPON) vs G.984 (GPON) <ul><li>BPON supports only ATM cells </li></ul><ul><li>GPON supports both ATM and GEM </li></ul><ul><ul><li>Generic Encapsulation Mode (GEM) </li></ul></ul><ul><li>GPON GEM efficiency </li></ul><ul><ul><li>Eliminated 8b/10b requirement </li></ul></ul><ul><ul><li>20% more efficient than EPON in carrying IP </li></ul></ul><ul><ul><li>5-10% more efficient then BPON </li></ul></ul><ul><ul><li>Long term benefits towards lower cost equipment </li></ul></ul><ul><ul><li>Support of packet fragmentation </li></ul></ul><ul><li>Benefits: </li></ul><ul><ul><li>Can choose solution that delivers lowest cost over time. </li></ul></ul><ul><ul><li>Clear migration path to an all IP network </li></ul></ul>
    22. 22. PON Standards - Summary <ul><li>GPON (G.984) improvements over BPON (G.983) </li></ul><ul><ul><li>Efficiency: dual mode support of ATM as well as Ethernet frames </li></ul></ul><ul><ul><li>Scalability: more economical means of achieving high speeds </li></ul></ul><ul><ul><li>Lower costs because of relax timing requirements and common optics with EPON </li></ul></ul><ul><ul><li>Supports TDM and Ethernet Interfaces at the OLT </li></ul></ul><ul><li>GPON Values </li></ul><ul><ul><li>Similar Cost points to BPON </li></ul></ul><ul><ul><li>Architecture/Platform that will migrate with the operator, without requiring forklift upgrades </li></ul></ul><ul><ul><li>Standards driven for interoperability </li></ul></ul>
    23. 23. <ul><li>PON Protocol Standards Matter </li></ul><ul><ul><li>Reliability & Availability </li></ul></ul><ul><ul><li>Mass Adoption/ Lower Costs/ Greater Flexibility </li></ul></ul><ul><li>ITU Is The Dominant Standard </li></ul><ul><ul><li>GPON is the dominant PON protocol standard </li></ul></ul><ul><ul><ul><li>SBC, BellSouth, Bell Canada, Verizon, International PTTs </li></ul></ul></ul><ul><ul><ul><li>Most Bandwidth = Most Revenue Potential </li></ul></ul></ul><ul><ul><li>Flexible & Cost Effective Transition to All IP Network </li></ul></ul>Summary

    ×