Transcript BT 21CN and UK National NGN Interconnect

NGN Interconnect Update
JOINING THE THREADS
25 May 2005
FOR WG DISCUSSION ON 3 JUNE
INTERCONNECTION TODAY
• Distance and Element Based
• Voice Stovepiped (snapshot below, as example)
• NNIs for Frame and ATM
• Partial Private Circuits using PDH/SDH
Site Type
“Ex-DLE RCU”
“DLE”
“Tandem”
“NGS”
# Sites
N/A
213
# Sites w/ ISI
32
82
6
56
ISI E1
Volumes:
-
2,449
1,598
54,455
IEC E1
Volumes:
1,686
2,163
353
19,616
62
NGN INTERCONNECT
• Converged Point of Handover
- Multi-service pipe between two operators
- Architecture (i.e. standards) to be agreed at TSG
- In 21CN, BT side will generally be at a fibre MSAN
• Service Specific Conveyance
- Multiple services will be conveyed across a PoH
- Some will be price controlled (e.g. PSTN), others won’t
- Some will require service specific network elements
- Some services can be defined today, others can’t
For discussion purposes.
No implementation assurances
CONVERGED POINT OF HANDOVER
• Convergence requires a glue layer
- Long term vision is native Ethernet, but
- Some services may still require SDH
- And most UK networks are SDH based
• BT Proposal to NICC/TSG
- Hybrid: SDH, Physical Ethernet and/or Ethernet VLANs
- Provides implementation flexibility
- Allowing for technology evolution
- But defines Ethernet VLANs as the glue layer
For discussion purposes.
No implementation assurances
IP IP IP IP
IP IP IP IP
Ethernet VLAN
Ethernet VLAN
ATM GFP
GigE Physical
GFP ATM
VCAT
VCAT
SDH
Physical
For discussion purposes.
No implementation assurances
TDM Services
ATM Backhaul Services
PSTN/ISDN Services
Other Services on IP
Other Services on IP
PSTN/ISDN Services
ATM Backhaul Services
TDM Services
DAY ONE PoH ARCHITECTURE
HOW DEEP SHOULD PoH BE?
• BT proposed PoH at ~130 Metro node sites
• Some Operators want deeper PoH, because:
- They have existing fibre assets that may be stranded
- They want to leverage LLU investments
- They want to intermediate the wholesale market
- They believe conveyance will be cheaper
• Ofcom wants deeper PoH, because:
- Policy of promoting infrastructure build
- Greater competition for backhaul
For discussion purposes.
No implementation assurances
POTENTIAL HANDOVER POINTS
CORE
DWDM
4/4/3
SDXC
P
Router
~10 Sites
Core Node
Metro Node
Metro Node
Voice/P
C
PE
Edge
~WDM
Edge
~WDM
P
Router
4/4/3
SDXC
Legacy
switch
function
s
Ethernet
PE
4/4/3
SDXC
Legacy
switch
function
s
~130 Sites
CORE
DWDM
BRAS
Voice
Voice/P
C
PE
CORE
DWDM
Ethernet
PE
BRAS
Voice
P
Router
Intra Metro Ethernet
Network
Intra Metro Ethernet
Network
Tier 1 MSAN Node
Tier 1 MSAN Node
Edge
WDM
FMSAN
T
A
M
T
A
M
Edge
WDM
CMSAN
FMSAN
Lega
cy
Lega
cy
~1500 Sites
CMSAN
MSAN Node
MSAN Node
FMSAN
T
A
M
MSAN Node
FMSAN
FMSAN
CMSAN
T
A
M
Legacy
CMSAN
T
A
M
CMSAN
Legacy
Legacy
~4500 Sites
MSAN Node
CMSAN
~5500 Sites
T
A
M
CMSAN
Legacy
For discussion purposes.
No implementation assurances
T
A
M
Legacy
CURRENT BT THINKING ON PoH
• Converged PoH as a new NGN product
- Independent of service-specific conveyance
riding on top of PoH
- Dimensioning starting at STM-1 for SDH or Gig-E
- Monthly port-based pricing with distance charge
if circuit leased from BT
• Handover Points
- Tier 1 MSANs co-located at Metro nodes
- For operators with existing fibre, PoH at
customer side of nearest Tier 1 MSAN
- For LLU operators, PoH at nearest Tier 1 MSAN
For discussion purposes.
No implementation assurances
SERVICE LEVEL CONVEYANCE
• Multiple services will co-exist on PoH
- Services may require specific network elements
- Commercials will be different for different services
• Highest priority is PSTN replication
- Needs both media routing and session control
- Pricing will be determined by regulator
• Industry innovation will require new services
- E.g. Multimedia, circuit emulation & bitstream evolution
- For some, pricing will be commercially negotiated
For discussion purposes.
No implementation assurances
SERVICE CONVEYANCE PROTOCOLS
C7 PSTN REPLICATION
SIP-I
RTP
MULTIMEDIA
ATM
SIP
PNNI
RTP
NGN PPC
Circuit
Emulation
SCTP
UDP
SCTP
UDP
Ethernet Glue Layer
Point of Handover
Note: ATM and Circuit Emulation over Ethernet subject to further standards work.
For discussion purposes.
No implementation assurances
ATM over
Ethernet
STANDARDS CHALLENGES
• Many fora developing open standards
• BT committed to NICC/TSG process
• Sourcing standards for consideration from:
- IETF, TISPAN, Metro Ethernet Forum, 3GPP, etc.
• But, localised variants cost time and money
- Balance between backward compatibility
and the burden of forever carrying the past
For discussion purposes.
No implementation assurances
SIP-I CONDUNDRUM AS EXAMPLE
• ITU ratified Q1912.5 for Global ISUP in SIP
• ETSI Plenary in September; expected to
have ratified European normalised standard
in December.
• UK NICC must agree and ratify the UK
specific variations and options to ETSI SIP-I
• Vendors will need to support multiple SIP-I
variants on a global basis:
• Will we back to the IUP problem in N years?
For discussion purposes.
No implementation assurances
CURRENT BT THINKING ON NGN
NARROWBAND CALL CONTROL
• Altnet ability for full call control of their customer’s
individual baseband voice line from their call server
• Altnet assumption was that this required physical
interconnect to MSAN line card H.248 gateway
• Mutual learning from Consult21 Engagement
• Proposed BT solution enables NGN CPS and WLR
for all wholesale customers
-
Provides full call control to those who invest in Call Servers
Not limited to deep infrastructure players
Promotes competition and innovative feature discrimination
For discussion purposes.
No implementation assurances
ILLUSTRATION OF AGCF SOLUTION
ALTNET 1
Equivalence
Demarcation
BT
Call
Server
Call
Server
SIP
ALTNET 2
Call
Server
SIP
SIP-I
AGCF
AGCF
“H.248 Proxy”
“H.248 Proxy”
MSAN
H.248
control
of line
card
MSAN
For discussion purposes.
No implementation assurances
CURRENT BT THINKING ON 21CN
NARROWBAND CONVEYANCE
• Ofcom will determine PSTN conveyance rates
- “Technology Neutral” NCC currently in consultation
- Market review will follow to set 21CN specific conveyance rates
• Industry needs commercial certainty during 4 year
interregnum when 2 PSTN networks overlap
- Non-congruent PSTN conveyance rates will be disastrous for all
- Creating new arbitrage markets; hurting sustainable competition
• New Wave voice products that do not rely on C7 and
PATS will follow commercial pricing models
- No SMP nor bottleneck
- Where all operators will try to innovate for new revenue
For discussion purposes.
No implementation assurances