Transcript Fall 2002 VON

Peer-to-Peer Solutions
Between Service Providers
David A. Bryan
CTO, Jasomi Networks
October 10, 2002 – Fall VON, Atlanta, GA
Why Peer?
• Cost Savings
– Lower completion costs
– Less new equipment
• Extend Reach
– New geographical regions
– Regulatory issues
• Opportunities to Partner
– Each may have good local client base/grasp of local
market
How Can Companies Peer?
• 3 ways to do this
– Use the PSTN
• Includes Back-to-Back gateways
• Lots of problems (cost, loss of signal, etc.)
– Open connections direct to each other
• Issue with firewalls/NATs
• Often Peers are potential competitors – don’t want to leak
information
– Use some sort of purpose-built device
• IP-to-IP Gateways
• VoIP aware firewalls
Specific Devices :
VoIP Enabled Firewall
In many scenarios, the firewall is
controlled by a Firewall Control
Proxy
Carrier A

Carrier B
Fire wall corrects the signaling, and
can open and close ports to allow
the media to pass
Both carriers may have similar deployments of firewall and proxy.
Specific Devices :
IP-to-IP Gateway
IP-to-IP gateway between carriers. Each side is
a new call. Generally, doesn’t use a control
proxy. Proxy terminates calls at the device just
like any other gateway.
Carrier A
Carrier B

(May be in DMZ using
existing firewall)
Both carriers may have similar deployments of IP-to-IP Gateway.
Issues with Peering
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NAT/Firewall traversal
Anonymization
Billing
Authentication
Legal Intercept
QoS Matching
Network mismatches
Protocol translation
Media codec translation
Network Security
Fraud detection/prevention
Demarcation Point
NAT/Firewall Traversal
• Carriers still want to
be able to connect
with firewalls
• Carriers may be on
separate IP spaces
• Need to be able to
interoperate
Carrier A
Carrier B
Anonymization
• Carriers may want (or be legally obliged)
to hide identity of the user who originated
the call, but still need to track it internally
Carrier A
Incoming call is
“anonymous”, but still has
traceable information
(i.e., IP address)
Carrier B
When delivered to Carrier
B, identifying information
may need to be stripped
Billing
• Billing is often generated at Gateways, but
gateway is in terminating carrier’s space.
Carrier A
Carrier B
Billing is
generated here,
but Carrier A
would like own
billing records
PSTN
Legal Intercept
• Again, intercept is often done at the PSTN connection,
but Carrier A may be legally required to provide intercept.
Carrier A
Boundary may be
only place in
network where
media and
signaling both flow.
?
Carrier B
PSTN
Authentication
• Need to be able to verify that users are authorized to use
service, and possibly check before call for prepaid. This
might need to happen on both sides.
?
Carrier A
Ok to Call?
AuthSrv
Carrier B
Ok to Call?
AuthSrv
QoS Matching
• Different providers may use different marking schemes
for QoS, and these need to be translated
Carrier A
?
Carrier B
Conversions
• Network Mismatches
– IPv4/IPv6, particularly between countries and as time
moves on
– Different Network designs (transport, physical media,
etc.)
• Protocol Conversion
– H.323 to SIP translation
– Various “flavors”
• Media Codec Translation
– Need to translate to compatible, but minimize total
number (particularly with wireless)
Network Security
• Want to hide information about your network
–
–
–
–
Who do you terminate with?
How many proxies or switches in the network?
What nodes were visited on this call?
Network topology
• Want to ensure no “bad” traffic from remote
network
– Prevent malformed requests that could crash servers
– Prevent malicious requests designed to disrupt
service, intercept traffic, or steal service
– Detect incompatible devices sending information to
your network and squash
Fraud Detection/Prevention
• Need to detect fraudulent uses, like multiplexing
multiple calls over a single billable call
Carrier A
3
Users are making
three calls
1
Bill is generated
for only one call
Carrier B
Demarcation Point
• Useful for trouble shooting
– Able to prove that flow is “good” up to the
edge of the network
• Generate statistics and metrics
• Leg to stand on when problems arise
Jasomi’s Product Line
Enterprise-to-Carrier and Carrier-to-Carrier Solutions
Visit us in Booth 234
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